(Check out the point that begins at 4:56)
If you have a hard time countering your opponent’s net approaches, try to do what Stanislas Wawrinka does really well here. As Novak Djokovic approaches the net, Wawrinka throws in a short slice which catches Djokovic completely off guard.
As you can see, it is difficult for players who are approaching the net to effectively handle short balls because there is not much they can do to a ball that is low and very close to the net. The best option is to pop the ball up as deep into the court as possible, but that is pretty difficult to execute and if even properly executed, the ball is easily attackable. So what every player usually goes for instead is to hit it short back, and Wawrinka knew that Djokovic would do this from a mile away. As soon as Djokovic made contact with the ball, Wawrinka was already racing to the net to put that ball away. Basically, it is a win-win situation when you feed the ball low to net-approachers.
This tactic is very effective and should definitely be added to your game. You will surely begin winning more easy points when your opponent approaches the net!