Hit your ground strokes deep to keep your opponent on defense.
The last two weeks we've discussed lobbing your opponent. If you're lobbing then your opponent is at the net. Let's look at one way to keep them from getting to the net in the first place...deep ground strokes.
If you watch the tennis pros play, you'll see that most of their ground strokes land well behind the service line, closer to the base line. Hitting the ball this deep reduces the angles that your opponent can create and makes them hit from a defensive position. In fact, many times, if the ball is close to the base line, you can cause an error from your opponent.
Here is a good way to condition yourself to hit the ball deep.
The next time you are practicing, hit a basket of balls from your base line to the opposite fence. That's right, I want your ground stroke to make it all the way to the opposite fence before it hits the ground. You really have to hit through the ball to hit it that far. This will give your shots better pace as well as condition you to hit deeper.