Serious learners of Japanese argue there are many ways to learn kanji and not all of them are successful or even slightly perfect.
What is most interesting about this article is not so much Koichi's suggested methods, but the comments below about all the different methods others have used to improve their kanji comprehension, retention and recall abilities.
I would suggest having a read and then taking a look at these comments as some of the suggestions really are very helpful.
What method do you find works for you? Share your ideas in the comments.