I've been told that the straight shot drill is ideal for building a strong foundation in pool, and I wholeheartedly agree. It's a stellar drill, primarily because it forces you to develop a consistently straight stroke, which of course pool is impossible to excel at without.

But it doesn't do much else, does it?

There's so much more to pool than shooting clean straight in shots. Sure, you can elevate the drill by shooting full table stop, follow, and draw shots if you're able, and even place the cue ball on the bottom rail and shoot from there, but even still you wouldn't be doing anything that works on the more nuanced aspects of the game like various cuts, left and right spin, patterns, and positional play.

So for those of you who've played for a while and fancy yourselves capable and well-rounded cueists, my question is this:

What drills REALLY helped to develop you the most as a player? Drills that, looking back, you can say were truly invaluable and necessary to help you regularly reach that next level in the game.