To prepare for tournament play properly, you have to accurately mimic the tournament playing environment in practice. Like Neil said, there is a lot of down time, and you never know when you have to play your next match. You have to prepare your mind for the unexpected.
Many players fold under the pressure of competition, but many players become victims of the social environment and social atmosphere. It is so easy to get pumped up for that first match, but so easy to lose that intensity BS'ing at the flowchart with other people.
In a tournament, your competition gets tougher with every match you win. What you do and say immediately before and after each match is extremely important. If you want to build a great model for conducting yourself at tournaments, look no further than Landon Shuffett.
Between matches, he examines players - he focuses on runout patterns of other players, watches how the different tables are reacting, he notes strengths & weaknesses of other players, and he basically just keeps his mind fresh.
Prior to every match, Stan takes Landon aside and they have some one on one player/coach time. It is amazing to watch Landon enter a match, take control of it, and then close it out. Once the match is over, Stan and Landon seem to turn the intensity up a notch for the next match. Landon goes through the tournament like a slow burn instead of an immediate explosion. I cal it controlled intensity. I think that there is a lot that we can all learn from that.
