Stay Away from the Net
One of the easiest ways to improve your game immediately, is by aiming higher over the net. Most players think that a great shot in tennis is fast and low over the net. They look at the net and aim just slightly above it, missing frequently in the net.
As you can see in the video, the secret of the pro game is to hit the ball high over the net with topspin. This will not only reduce unforced errors but also keep the shots deeper.
Next time you are on the court, keep track of your net-mistakes and adjust accordingly. Aiming a foot higher can make a huge difference in your game.