I'm by no means a great player but to answer DanQ, I have noticed that if you turn the sound off on a machine (or wear headphones I guess) you'll do alot better. I think it pulls the excitement out of it, you're just flipping balls at lights then.
Also, I think to be a good tournament player you have to be able (or willing?) to take the fun out of pinball. Don't go for beating the game like someone else said just find that one safe shot that will build for you and shoot it over and over. I would hate to play like that but I've watched people just pick a shot and loop it over and over to slowly build points, that doesn't seem like much fun to me but it does seem to win tournaments.