I've found that mnemonics really only help at the very beginning of learning. But once you even get to 100 things you need remember, a completely unrelated extra thing you have to remember on top of what you actually need to learn becomes too much.
For kanji, just remember the radical readings, and memorize vocabulary with the different readings of the kanji you're trying to learn. Knowing that 貢献 sort of kind of sounds like cocaine does nothing to help me remember that it means contribution. But knowing 献血 and 献金 help me memorize that けん is a reading of 献
For kanji, just remember the radical readings, and memorize vocabulary with the different readings of the kanji you're trying to learn. Knowing that 貢献 sort of kind of sounds like cocaine does nothing to help me remember that it means contribution. But knowing 献血 and 献金 help me memorize that けん is a reading of 献