Learn How to Find and Attack an Opponent's Weakness:
One of the best strategies is to attack your opponent's weakness. If you know your opponent well, then you probably know his/her weakness. However, if you are playing someone you’ve never played before you don’t really know what to expect. What you can do is, during the warm up, hit a different variety of shots to both forehand and backhand. Give him/her a high topspin shot, or a low slice and see how he/she reacts to the shot. Once you find a weaker side where the person makes a lot of mistakes from, then you can start attacking that side. At that point your game plan should be hitting your shots towards the weaker side. When you can do that, over the course of a match, you’ll win most of the points and the match.