Holdem is a not a game where you can obsess about preflop play, unlike stud and omaha. Get pokerstove and start running numbers on hands that you have played. This will help you identify leaks in your hand ranges against other players. This is really one of the most important skills you need to learn to kill limit tables. Its a lot easier to play once you know what you are up against. Once you have that done, the rest falls into place.