I'm not sure I can add a lot to this conversation. Most of the salient points have already been made by some of the most knowledgeable members of this forum, but I can add my perspective based on my personal experience. For me drills and repetition are the best way that I learn. When I'm just playing or shooting around shots would come up that I wanted to learn to execute, but they came up randomly and usually involved multiple variables for position based on the table layout. I couldn't key them in my mind to come back to them. When I started doing drills I picked drills that isolated techniques, shots, or positions that I needed to work on. When I was able to key in on those items specifically and focus on learning that one technique, shot, or method of execution I could recognize it when it came up in a game.
Apart from that doing stroke drills by themselves helped straighten out my cue path considerably and made me more consistent overall since I was just focused on making a good stroke and not pocketing a ball, using english, or getting position.
