Going back to the Tournament Preparation: Chess Skills and Mental Toughness posts, your skills practice over time should boost your strength (and it's good to put extra focus on some things pre-tournament). However, it's your ability to maximize your chances in each individual game that determines your actual performance. "Cramming" for a chess tournament like it's an exam is not helpful, since there's simply too much information to deal with; an exam has a finite boundary (even if it seems like a lot), while chess does not. That's why optimizing your own mental and physical state - being as relaxed, energetic and confident as possible - will do more for you in the short term when going into a tournament. Because chess is also a creative and engaging activity, I think this is even more important, since purely rote memorization and application of ideas generally leads to failure.
A recent post over at the Chess Improver ("Tournament Prep for Older Players") contains some similar themes. The author (Hugh Patterson) has some more specific suggestions for pre-tournament activities, which you may or may not follow - IM Josh Waitzkin and others have also focused on Tai Chi practice as a blend of mental and physical training - but the main point is that getting your mind and body in a good place is the best way to set yourself up for success in both the long and short term.
|IM Josh Waitzkin|