I remember back during the Summer when I was working through most of RTK 1, one of my biggest problems was with keywords that were either difficult to keep separate (anti- not nothingness negative negate, fat obese round, you get the idea) or simply too abstract and short to build any significant memory on (un-, re-, or again, etc., so on and soforth). The following is my technique for hinting the actual kanji being requested, so we can stop failing cards for forgetting the keyword-kanji mapping and start failing them for forgetting whether the damn dog is a real dog (犬) or just big (大) for the ten thousandth time.

This method is really built around two things, though, which I should say up front: the first is a reasonably extensive knowledge of Japanese. For people doing RTK in The Recommended Order, someone else is going to have to help them out. The second is the ability to add text to the card front, so either an offline SRS or this site plus Firefox plus that Greasemonkey script.

The basic idea is to, on the cards you have trouble keeping straight, add some disambiguation text. For example, on re- (戻), I have the following:

「もどす」や「もどる」の「もど」

Which is enough to nudge me onto the correct train of thought. Similarly, for wish (念), which I could never keep straight with 願 and 望 (the former especially, thanks to CLAMP), I have the following:

「ねん」や「残ねん」や「無ねん」の「ねん」

Which sets me straight.

So anyway, that's what has been working for me, I hope someone else finds it useful.

~J