Me three. I don't bother with mnemonics. I'm lazy, so I let repetition do the trick, and if I have problems remembering, then I just add extra sentences, and that usually does it. I follow that up with lots of reading/listening in Japanese, too, so I'll oftentimes catch whatever it was I was studying "in the wild" for further reinforcement. Like I've said before, my long-term rate is right around 96%, so it's not worth the extra effort to get 1-2 more percent. If I was having problems, or my rate was much lower, then yes, I would consider something like mnemonics.