The best way to learn kanji is by memorizing radicals. Most of these building blocks of kanji are taught at introductory kanji textbooks, but they are not introduced as such. The book "Essential Kanji" introduces kanji in a way to make one aware of the radicals for what they are. A second aspect of learning kanji is knowing the pronunciation of the sound elements, which the above mentioned book does very well. The final aspect is using kanji as much as possible. If you intent to recognize the kanji and not forget them, constant exposure is necessary.

The best way of learning kanji: repeat, repeat and then more repetition. Honestly, this is for me the core question of learning Japanese. For the first 200+ kanji it might be possible to remember by pictures (the easiest example being yama/mountain), but after reaching a decent level, the effort of making up pictures or stories becomes higher than the effort of just memorize by repetition. Reading a lot, writing letters by hand (!!), these are the methods of learning and not forgetting again.

In connection with Michael's advice of using kanji as much as possible I found it of good use to observe the correct stroke order. Actually, the rule in which order to write the strokes includes some kind of efficiency. Also the beauty of the Kanji is best achieved like this. To my opinion, writing Kanji and not observe the right stroke order makes them look awkward.

I think it's difficult to write kanji. It's a good way to learn with a focus on reading kanji. anatno pasokon wa nihongo ni henkan dekimasuka?