Fool your opponents' expectations about depth. In
volleyball, when the opponent goes up to block an expected spike, you can often score by hitting over her into the empty space behind her. The key is deception. Use the same kind of tactic in tennis, especially with your slice shots, where you can either drive the ball deep or hit a drop shot. Once you've hit a few good drop shots, your opponent will often move forward when she sees you getting ready to slice. That's the perfect time to drive a slice past her for an easy winner.