I have been watching the Dan Heisman Q & A for a while now and have seem a very frequently asked question: I'm a 1600, and play frequently in tournaments. How can I get better?
Well, there is one simple answer. Practice! Practice always makes perfect.
I may be a hypocrite for saying this, because before I was always trying to get out of playing chess. Now, since I play in many different tournaments and play in opens, I have realized that practice is the best way to.
Like Dan Heisman says: "Don't play computers, play people!" Computers will go after material, not strategy. Though computers have the upper hand in calculating ways to get more material, the human brain outsmarts them by using strategy.
So practice! That's the way to win! Don't study and study and not play any games before the tournament. You can study, but make sure you can practice those methods before it really counts.