Don't skip warming up and cooling down for all your matches and practice sessions. Doing so will result in sore muscles and injury.
Be aware of where you are hitting your shots. Don't just blast the ball hard up the middle. Look for hitting the ball low sometimes, practicing rolling passing shots, lobs, and find corners of the court.
Try to construct points against the 2 players by using combinations. For example, practice hitting the ball directly down the center and then bring the ball out wide to catch your opponents out of position.
Run every ball down. There is no out ball in this drill. The idea of this drill is to work your shots and body to the max.