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.