If you want a "how to", there are plenty of crappy blogs out there with opinions on The Best Way to Learn Kanji, many of which might work for you, and others that tell you to imagine Kanji as people bending over looking at their shoes, or to create nursery rhymes to help you remember Kanji, or whatever, but rather than reinvent the wheel with another "This is the best way" blog post to add to the confusion strewn about the internet, which never really works anyway, we got a group of people together who have reached some sort of relatively respectable level of Kanji learning to talk about their experiences learning Kanji. Not only will it probably not give you The Best Way to Learn Kanji, but you'll probably find contradiction and contention below - why? Because there is no BEST way, just the way that works for you, which will involve hard work and annoyance, and be anything but easy. The following is the experience of people who've already been through it, and more or less pulled it off. So go forth and be schooled. Just keep in mind - your mileage may vary.
First, we'll start with Chris, host of the Samurai Archives Podcast (mostly for convenience since I'm writing the introduction anyway)...
My interest in the Japanese language was fueled by my obsession with the martial arts in high school in the early '90's. I somehow got my hands on a tiny Japanese-English and vice-versa dictionary which had a list of katakana and hiragana in the back. I started teaching myself katakana because it seemed a lot easier to write than hiragana, and I quickly realized I could write out test answers on my desk in pencil in katakana, or even blatantly in pen on the back of my hand, which freed me up to do things more important than studying - it goes without saying that 20 years ago, teachers in Small Town USA didn't even have a concept of a non-European language, let alone written Japanese. At this point I think I just wrote out the katakana until I had it memorized. The idea of flashcards never even hit me at this point.
Once I got to college, I started taking Japanese language classes, but at this point, although I did have a heavy interest in Japanese, I didn't have a heavy interest in studying. I was able to pull in As and Bs pretty easily without studying, so all I really accomplished was to get a pretty good grasp of hiragana, katakana, and probably about 50 kanji in the first year.. Fortunately I spent the next year in West Bumfuck, Japan, and that's where I got serious. Things seem to have changed quite a bit in the last 20 years, but when I got to Japan, all anyone ever told me about was how "foreigners can't learn Japanese", and since I have a belligerent streak when it comes to people telling me what I can't do, and since I already had hiragana and katakana in the bag, I started on Kanji with a vengeance. We learned a handful a week in grammar class, but that didn't even remotely come close to satisfying my desire to get ahead, so I started with a few angles. I stole a kanji dictionary from the library, which included illustrated stroke order (I still have this dictionary, in fact), and collected Kanji to learn by picking up a random manga (the first of which turned out to be a first edition Battle Angel Alita - although it wasn't called that at the time), and starting on page one, looked up the kanji in the dictionary, and wrote them thousands of times. I use no hyperbole here. I literally sat in the library probably about 4-8 hours a week, every week, writing so much Kanji I would use up every single piece of paper with any available space for writing on it in the library. Running out of paper would essentially be my signal that it was time to put down the book, grab a few gaijin dorm mates, and ride our Wizard of Oz bicycles down to the beer machine at the bottom of the hill and start the evening's festivities.
On the subject of Kanji dictionaries, people don't seem to realize the value of looking up Kanji in a dictionary - a paperback, non-electronic dictionary. It forces you to learn the radicals (the parts that make up the kanji), and it forces you to be able to get an accurate stroke count for the Kanji. Also, and I see people rail against this all over the internet, but you not only have to learn to write Kanji with the correct stroke order, you gotta write it a metric shit ton of times. After three months of my insane kanji writing marathons, I suddenly hit a critical mass. Let me explain.
When I first started learning Kanji, it literally looked like a random collection of lines, and I had trouble even getting an accurate count of the number of strokes, and I sure as hell couldn't write it in the correct stroke order without looking at my handy-dandy stolen dictionary that illustrated the stroke counts. But suddenly, around the third month, something in my brain changed - I could look at any Kanji, even one I had never seen before, and I could instantly know the correct stroke order, and I could count the number of strokes in my head. As an aside, the first three months in Japan listening to spoken Japanese, I had to translate it in my head into English, and then I would understand it, but right around the same time in that third month, suddenly I was sitting in class and I realized with not a little bit of shock that I was no longer translating Japanese into English in my head, I was just understanding it. A brain seems to need a certain volume maintained over a certain amount of time to reach a critical mass where things suddenly change. I think it's similar to learning an instrument. For a while you're just playing notes and mimicking things and memorizing things, and then suddenly BANG everything changes, and you can actually play.
But, back to the Kanji. So, for me, writing Kanji a gazillion times, as boring as it sounds, internalized it (it's not just "memorization"). Oddly enough, I'm pretty sure that even at this time I still wasn't ever using flashcards. I was reading newspapers and such, noting Kanji I didn't know, then writing the everloving shit out of 'em. So I think at the point I left Japan after the year was up, I probably could write around 500 Kanji, and probably read twice as many. People don't realize that reading and writing are two unrelated skills. Currently I can easily read three or four times as many Kanji as I can write. I see it and can read it, but since I don't ever write anything by hand (computers don't count), I've gotten pretty limited in what I can recall in order to write out by hand without looking it up.
A few years later, I went back to Japan, and started using flashcards. Every sign I saw, or every TV show or movie I watched that had Kanji that I didn't know, I put on flashcards, which probably resulted in about 500 flashcards of jukugo (two-Kanji combinations), or words. And at this point, I could knock out most of a newspaper, or read any random novel by Akagawa Jiro and barely crack a dictionary three times. Flashcards worked great for my reading. If you learn jukugo, you basically learn the On'yomi for both Kanji, and next time you see one of them with something else, you've already got half the word read (feel free to utilize Google if you need a definition of On'yomi and Kun'yomi - but it's basically the two main different ways to read Kanji). So I've always been a fan of flash cards for quick recognition, which you can then solidify even more as you read. But again, they do very little, if anything, for writing.
Now, in this day and age, you really don't need to learn how to hand-write any Kanji - I can type out an entire letter with barely a hitch in Japanese because hitting the magic space-bar gives you a list of Kanji, and if you can read 'em, you can pick 'em out of a line up. But the experience of writing out Kanji by hand is important not just because some teacher says it is, but because it is also a learned skill, and learning it seems to do something to your brain that I can only assume is good, and probably useful for something. I didn't major in Neuroscience, so that's as technical as I can get, although I have read that learning multiple languages changes structures in the brain, which seems like a good thing, expanding the brain and all, but damn it's annoying when you're speaking to someone in English, but you can only come up with the Japanese version of the word you need in your head.
So, I guess my experience is as follows - writing Kanji using the correct stroke order eventually allowed me to eyeball any Kanji and be able to reproduce it correctly and immediately with zero practice. Being forced to look up Kanji in a paperback Kanji dictionary forced me to learn Kanji radicals, and be able to get a quick and accurate stroke count, as well as be able to pick the Kanji I was looking for out of a long list of similar Kanji listed in the dictionary (If you've seen a Kanji dictionary, you'll know what I mean). Flashcards created from what I was reading or looking at meant that I would continue to use them in practice as I read related materials or looked at store signs or what have you - the more you see/read the same Kanji, obviously the better you retain it. I really can't speak to the mnemonic devices. I never used them. I feel like they are pretty worthless unless you need to remember 15 Kanji for a test. In that case, I can see it being useful, but you are not going to be able to read a newspaper by looking at every single Kanji and try to remember how it looks like a sea otter balancing a butterfly on its nose. Just do the work, slacker.
Next up is Rick Noelle, a software developer in Atlanta, and alumnus of that same school in Western backwoods Japan as Chris, above.
I started studying Japanese after taking a job in a Japanese restaurant. Initially I focused on listening and conversation but eventually added reading and writing. I started by memorizing hiragana and katakana and then took up Kanji. While studying Japanese in college I would practice the assigned kanji but I also liked to study extra on my own. Ultimately I fell back to the order taught in Japanese schools. I basically use that as a basis but also supplement it with Kanji found in things I read for fun such as newspaper articles, manga, etc.
I think the best advice is to accept early on that there is no secret method to learning Kanji quickly. It basically boils down to hard work and finding the system that works best for you. I've tried many methods including those that are supposed to speed up the process such as James Heisig's Remembering the Kanji. Those types of systems never seem to work as well as you'd like unless you are really committed to author's idea of the best way to learn. But you might discover something about the system that you like so I think it's a good idea to try many different approaches. In the end you can take the bits and pieces from each that you find appealing and mold them into your own custom approach. One example from my own experience, I basically memorized all the Kanji radicals and have a unique keyword assigned to each that is based on it's actual etymology. When I look at a Kanji I think of it as a collection of radicals rather than an individual entity and I try to come up with a mnemonic based on the radical meanings that aids in its memorization. But since I am sticking to the 200 or so radicals, I don't need to study the Kanji in any particular order (like you must do in Remembering the Kanji). This allows me to study them in the same order that they are taught in Japanese schools but also employ some of the parts I liked from RTK. But again I think it's worth pointing out that there isn't a secret formula to learning Kanji and I don't think you can ever be "too good." It is something you must enjoy studying and accept that you will probably have to keep studying it as long as you are interested in Japanese.
One additional point I'd like to make is the importance of a good dictionary. It can be a little daunting choosing a good one when starting out because there are so many to choose from - compact, comprehensive, etc. Since you will be using your dictionary a lot, it is wise to take your time and select one with features that match your needs. For day to day study, my personal favorite is Kodansha's Kanji Learner's Dictionary. One nice feature is it lists kanji compounds with the target Kanji in varying positions - lead, middle, trailing, etc. Many dictionaries will only show compounds where the target Kanji is in the lead position. The point is to be aware that not all dictionaries are created equal and it pays to shop around. A good dictionary can make the difference between enjoying Kanji study and dreading it.
Travis, a graduate student in Japanese history, and another host of the S-A podcast, also weighs in:
I started studying kanji, I guess we could say out of necessity. I taught myself kana while I was still in high school (using the "Let's Learn Hiragana/Katakana" series) and then began taking Japanese in college, initially out of interest in video games, though I very quickly became less interested in video games, and more in history and traditional culture. But, when I was in college, obviously having to study Kanji as part of studying the language, I never enjoyed Kanji very much, and in particular always struggled very much with it.
To study, I basically just used whatever methods we had from class. I might have used flashcards - I don't recall - but I never went out of my way to try any range of different methods or tricks for learning kanji.
Early on, if I remember right, it was mostly just a lot of repetition - the sort of "go home and write these Kanji 20 times" (or 100 times, or whatever it was) kind of homework assignments. And then, I guess, homeworks or quizzes that gave us either the kana, or the English, and asked us to provide the Kanji or the other way around. And, of course, later on, getting into practicing Kanji by reading and writing whole sentences, and then whole paragraphs. But I don't remember any of this really working for me. I don't remember having too much trouble with what was assigned to us, and I guess I graduated college knowing fairly well the majority of Kanji that I had learned, but that jump from the level of language ability one has after four years of college language classes, to the level of language ability where you can actually read whole articles or books, and otherwise function in a relatively functional way in Japan, or in Japanese Studies, that's a pretty big leap, and that's where I really struggled.
Then I went to the Inter-University Center (IUC) in Yokohama, and, not to sound like I'm shilling for them or whatever, but, whatever they did, it worked amazingly. We were given a number of Kanji to learn every day, and were basically just left to our own devices to learn them, and to submit quizzes proving we learned them. It was left up to us whether we did one quiz a day, or five once a week, or ten quizzes at once only handing them in once every two weeks; and then we would go over the quizzes with our sensei, briefly, once a week, one-on-one. Since we didn't have a "Kanji class" or anything and were pretty much left to our own, I guess I can't say that anything special happened there either with methods, but I guess just being forced to work on it so intensively (ten characters a day or whatever it was, every day for a full school year), while being immersed in language classes - reading and writing in Japanese for so much else of what we did every day - made it work.
I don't know what aspect of the IUC experience it was - whether it was so intensively studying all the Joyo Kanji so many every day; or the immersion element; or the radicals realization - but somehow it was like a switch was flipped, and I became able to learn Kanji and to remember them, and figure out new ones, so much more easily than ever before. And suddenly I was memorizing and recognizing, especially, some of the rarer and more complex Kanji from placenames (e.g. 薩摩), not to mention alternate versions of characters - (e.g. 學、壱弐参) with little difficulty.
And, perhaps most importantly, as a key element to the effectiveness of it, was the realization, of how radicals work. Apologies for over-generalizing, but I think most people who have never studied Japanese or Chinese feel terribly overwhelmed or intimidated by the sheer number, and complexity, of the characters. As did I, having somehow never been taught up to that point, or never fully realized, the extent to which most characters are made up of recombinations of the same set of elements. So, really, you don't need to memorize characters stroke-for-stroke, but only as a combination of elements (some of which are true "radicals" and some of which are not). The 'kei' of keizai 経済 is a fairly complicated, difficult to remember, early/basic Kanji I think, and I remember having a lot of trouble with it when I was in my first or second year of Japanese classes. But, really, it's just the ito-hen 糸, do 土, and mata 又, not that one needs to know the names or meanings of these, but just to recognize them as standard elements, rather than thinking of them abstractly as a singular, unique set of 11 strokes, and memorizing each Kanji separately as a whole character unto itself. And then, the final bit of this, is the importance, or usefulness, of radicals as indicators of meaning and pronunciation. This was huge for me. I guess it must have been explained when I was in undergrad, and I guess I never really got it. But once I was being exposed to a whole bunch of different, but closely related, characters, I began to pick it up so much more quickly, and of course, today, as I'm reading through a document, I may not recognize (let alone be able to reproduce from memory) every single character I see, but I can almost always infer the reading (pronunciation), and from there figure out the word just by sound, by pronunciation.
Nate, Army officer, aspiring scholar, and another host of the Samurai Archives podcast, helps us to wrap this up:
For me, Kanji study has always been, and always will be, about flashcards. I don't mean that nifty cool virtual flash card function you have on your electronic dictionary, or nowadays on your iPad or other similar device. I mean taking those little strips of thick paper on a binder ring, writing the Kanji character and some common combinations it is in on one side, and the furigana readings, meaning, and definition of the combinations on the others. Then going through them forwards and backwards: forward, looking at the character and writing out the readings and the meaning; backwards, looking at the meanings and reading, and writing out the Kanji.
Let me stress: WRITING OUT the Kanji If you can write a Kanji then you can recognize and read it. If you only study the reading, or think that electronic version of study is doing enough, you are wrong. You can't write if you don't practice how to write, but if you practice how to write, then you can write AND read. I can't stress that enough.
I've seen all the mnemonic stuff, the Tony Busan's or whatever, and if that works for you, then great. It never has made sense to me. I know it's all "new education" to trash rote memorization, but if I try to imagine a story for every Kanji I see, I'm wasting time and filling my head with nonsense. I've memorized Kanji by memorizing the radicals in it and how they compose it, but I'm not making up stories about the moon and the sun and the rabbit in the moon and all sorts of nonsense. Just do it--make the cards, study the cards, write the Kanji, and you'll remember them. Stories are just distracting to me.
The next step is to read. I'll admit, I'm much worse and much less disciplined at this than I should be. But pick up a book--doesn't matter if it's a manga or a novel--and start reading. Whenever you run across a Kanji you don't know, pull out your electronic (or other) dictionary, look it up, and make a card. Use the word you found it in as one of the vocab words you put on the card. And then continue on. Every so often, pull out your cards and run through them as a refresher. This builds vocab and cements the Kanji in your head. Could you imagine making up a silly story for every Kanji in a newspaper or book? I don't have that kind of time. Just make a card, move on.
So, that's how the people who have done it, did it. Take from it what you will. Hard work will probably get you pretty far, so do the work, or go find a magical shortcut to learning Kanji, and good luck with that.