Well, I'm almost at 400 frames so far, and for the most part I've been using word mnemonics. I tried to visualize pictures in the beginning, but when review time came around I would remember the kanji based on the words of the story, not on a picture. After finishing up to Lesson 16 this way, I tried to use pictures for Lesson 17. It didn't work out the way I had hoped; instead of my usual 85-95% retention, I ended up with 35%.

My question is, has anyone completed RTK using mostly (or only) word mnemonics? I've always heard that word mnemonics don't work out well as you cover more and more of RTK. If that's true, is there something I'm missing to the visual pictures method that Heisig doesn't cover?

Hmm, I'm at frame 670, and I find that coming up with a solid visual really helps my retention rate. If I can't come up with something really simple and memorable, then I try to make a story out of the elements. Failing that, it's rote memorization of the elements or strokes, which works fine for primitives that I have to write over and over again, and really poorly elsewhere. Looking over Lesson 18, I'd say that I have visuals for 31 of the frames, stories for 39, and I memorized the remaining 10 by rote. Just remember that after around the 500th frame, Heisig isn't going to give you much more help and you'll have to come up with stories on your own. I didn't really begin to focus on trying to create an image for each kanji until I reached this point.

While reviewing, it sometimes come to pass that I find a way to upgrade my story to the next level, either a rote memorization into a story, or a story into a complete image. I always seems to remember the character more easily after that. I guess the thing to do is to use what works for you and to keep moving forward.

I used a LOT of word mnemonics. They stuck with me better. Rhymes, jokes, puns...it was all about playing with the words. The problem I had with visualization is that the connotations of the words could change depending on how I was feeling on a certain day. This wasn't a problem for the short term, but if I hadn't seen a keyword for a loong time, I'd be like "wtf?" Words never change. "Spine" and "Shrine" will always rhyme.

If you're just using words to remember "Shrine = House + Spine," then you're setting up to forge it in the long run. But if you go with "A house with a spine, Shinto Shrine!" (big ups to whoever contributed that one), you'll remember it better.

Basically, whatever works for you. The downside being you don't know what works out until down the line.