Gregory's Server@kytta I can't recommend a typing trainer, for me it was too late, I was too fast using my own system to reap the benefits of re-learning...
What I have heard over and over though: try to get an unprinted keyboard, so your fingers get used to orientate using the two "blobs" on f and j alone
@schnittchen An unprinted keyboard doesn't help, because I have memorized the key locations with my eyes (but not my fingers). So, paradoxically, I can type on an unlabeled keyboard, but I can't type without looking down on the keys :D