Don't waste your time, and blow out your shoulder doing too much "mindless" serving.
Step one is to have a really great swing, and using your leg push off, coiling/uncoiling and bow/reverse the bow to poser your swing.
Better to shadow that swing until it is "perfect" - and then learn to toss into your swing.
(Too many let faulty tosses alter their swing.)
Do the thrower's ten exercises to make sure your rotator cuff and arm are ready to do all that bashing:
Make sure there are no technique problems in your serve that could result in shoulder problems:
Preventing Rotator Cuff Injury http://www.youtube.com/watch?v=lTRvxaBMh8s
Your serve technique doing more harm than good?http://www.youtube.com/watch?v=GgdXawklcZk
Rotator cuff injury http://www.tennisresources.com/index...v=1&vidid=3712
Listen to your body and don't be afraid to leave early rather than "too late".
Better to start your serving program by starting with 50 serves in a session and slowly increasing, rather than starting too high then being forced to take time off.
After taking say 20 warm up serves, consider playing simulated games.
In your simulated games move your serve around in both the deuce and ad court, for both your first and second serves.
The simulated game approach keeps the mind sharp in practice, and even helps prepare you for the thought process in match play.
(Of course if you are having trouble with a particular serve or placement, you can always take a few more to develop "muscle memory", then continue on with your game.)