Playing the right tactics is one of the vital keys to winning your next match.  In order to know which tactics to play, it is often helpful to label your opponent as a looper, chopper, lobber, blocker, etc.  Once you have placed him in a category, then you can begin making a game-plan.  (please realize that many playing styles overlap)
 
Check out these tactics articles on playing specific opponents:
 

Did you ever wonder what a 2500-rated player was thinking during a match? What thoughts were going through his head? What were his initial game tactics and how did his tactics change during the match?

 
 
 
For those of you who are preparing for our Sep 26-27 tournament, I would highly recommend that you carefully read this article and takes notes in order to mentally prepare for the competition.  I posted this article in the past, but decided to re-post it as a refresher...