I can't upvote this enough. I went from 200-300 Kanji characters that I acquired painfully to now 2053 Kanji characters using RTK in about four months. I use Anki (http://ichi2.net/anki/) to do reviews, but the Kanji koohii site is awesome for stories and has a nice active forum. I keep track of my progress here: http://kd7yhr.blogspot.com/
Are you learning just the meanings, or the meanings, kunyomi, and onyomi?
I ask, because I'm somewhere in between ２級 and １級 with the JLPT, and since I've only spent a collective six months in Japan, it's a bit of a struggle sometimes to retain vocabulary.
I'm finding that I have a very easy time with the meanings, and so I can figure out new compounds pretty easily. For example, in the novel I'm reading last night, 脱皮 came up, and although I figured out the meaning (a snake shedding its skin, a crab moulting, etc.), I still had to look at the dictionary because I couldn't remember the onyomi for the first character, even though it's very common.
Reading out loud has helped a lot, and I'm going to start blogging in Japanese about starting a company, but I'm always looking for tips on improving. :)
Newspapers still send me running for the dictionary, but I think that's because I read a lot of articles about politics and business, which are very kanji-heavy.
at first, I focused on production of kanji from a keyword, e.g., discuss -> 談, at this point there is no Japanese and I spent four months getting through all the kanji. I still test daily and have gone through 21k kanji tests.
Currently, I am reading みんなの日本語 wherein I am focusing on sentence mining and grammar. My current deck of sentences is around 800 sentences that I review as well, wherein I review recognition and speak out loud. My level is currently in between basic to low-intermediate. In the sentence mining I learn the readings of the kanji in context and could care less about kunyomi/onyomi, e.g.,幼稚園 -> ようちえん (or infancy-immature-park in RTK keywords).
I studied Japanese for 12 years half-assed never getting anywhere. For the first time I am making progress and I have a plan (which is the part that I lacked before).
BTW, to retain vocabulary, I would recommend Anki http://ichi2.net/anki/ it is open and regularly updated.
