From watching Pros on accustats:
The better players establish a preshot routine, and rarely dog a shot doing what we amateurs do, which is dogging a shot because we one stroked it.
From watching John Ditoro, Tommy Brown, Toby Sweet and other south florida champions:
Play all games, each particular game stresses different aspects of pool that will make you an overall better player.
From gambling against ball bangers to pros:
Don't let your opponent dictate the game, table or bet unless you have the nuts.
Don't donate to better players under the assumption that doing such will make you a better player. Make the game tighter, it will force your opponent to play an elevated game, which in the end will make you a better player.