I have always typed up detailed notes and documented what we were taught and learned. This includes pictures of targets so I can remember drills and techniques. I review the notes periodically as a refresher. Then I practice the techniques at the range, at home with my SIRT and even some things without a gun in my hand walking the empty halls at work if I’m the first to arrive or the last to leave. I imagine scenarios from training and ask myself if I could make the shot in my particular environment.
For examples of my training notes:
And here: Rob Pincus Training - #18 by Sinbad