I just finished my third week in league. I have been shooting pretty decent (I am at the top of the leader board in wins, points, game average, power average), so I started getting a little lazy on my practicing. Since I thought I had been shooting pretty good, I thought I would try my hand in a local tournament last night. I shot completely horrible. This is enough motivation for me to get back to the table for at least two hours a day.
Like Neil said, get into an organized league and set some goals for yourself. Get into some tournaments and see how you size up to some of the other players. Last night I lost two in a row, in a double elimination format. The thing is, I know I should have beat both of those guys.
Good luck,
Mattman