How to Play Tennis
1. Eyes shut
Once you've developed a sound service motion, it's important that you toss the ball into the same spot each and every time. You should be able to serve with your eyes closed, because the ball should be in the same spot every time.
2. Knock Knock
The key to having a powerful serve is in creating a loop in your backswing and letting your racquet head drop behind you as you toss the ball. This lengthens the swing, and more length means increased power. Serving requires using the big muscles of the body. Ask Pete Sampras, Boris Becker, or Goran Ivanisevic where their power comes from and they'll say their legs, hips, and shoulders.
3 .Same as it ever was
When you're practicing your serve, go through the same pre-serve rituals you use during a match. Bounce the ball a few times, bring your hands together, and then come to the set position. It doesn't matter if you hold your hands high or low, or how many times you bounce the ball; just do it the same way you would in a match, every time. The idea behind practice is to create consistency through repetition. If you don't practice your rituals, they won't be worth employing during a match.
4 Power plays
Looking to add more power to your serve? Here are two things you need to do:
1) Stay relaxed. When trying to hit the ball hard, most players tend to tighten up. Try to keep both your arm and your hand loose.
2) Don't be afraid to use your entire body. Turning your hips and shoulders and getting more leg drive into your motion will add power to your serve. The one thing you can't afford to do is only use your arm. The whole body needs to be part of the service chain.
