Okay, here's the Dave Hodge (my former coach)...
...serving drill:
- Go back to the service line, no racket, no ball. Just start doing a throwing motion, just as if you were throwing a baseball.
- Once that feels good, start throwing a tennis ball. Make sure to throw it up and out. This is the "throwing your racket up to the sky, then snapping the wrist" concept.
- Once you have that wired, throw one ball up with your non-racket hand, make sure it gets well up above your head and in front, and fire away at it with your throwing hand.
- Once that feels good, start with your racket in the back scratching position, toss, and snap! the ball down into the court. Try to bounce it as high as you can.
- That's the motion, now go practice overheads. Start in the ready position, when you see the lob, turn sideways, non-racket hand up and pointing toward the ball, racket held loosely but straight up in the other hand. Ball comes down, time it so you drop the racket into the back-scratching position, and pop it just as in the snapping drill, above.
Now you have an overhead, this will naturally elide into a serve. Some concepts on the serve...
Having said all that good stuff...here's some stuff my last coach (Sam Winterbotham, currently Head Men's Coach of the Tennessee Vols) told me that really helped straighten out my serve:
- Re your toss, as many other people have noted, it's not a toss, it's a lift. You're trying to place an egg on a mantlepiece. If you throw or toss it, it'll break.
- Beginners are taught to start the toss and backswing at the same time. The best servers get a lot of the backswing done before the toss. If you toss early, you have to adjust your swing to where the toss happened to end up. If you get a lot of the backswing done, you have a better chance of placing the ball where you want it for whatever you're trying to do with the serve.
- The power servers are using a Continental or even a little over toward the forehand grip from that. If you get into what is really a semi-Western backhand grip, you may get more spin, but you'll definitely cut down on the power, and you may not be able to direct the ball very well. Use Continental and adjust the swing path to get whatever spin or direction you want.
- The best servers are using a relatively simple, abbreviated backswing. Like a lot of other things in life, simpler is usually better. My backswing starts at waist level, goes out and up. I don't drop the racket to make a big loop. The fewer curlicues you have on your service stroke, the easier it is to come up with a toss that's as high as you need and no higher. If you have a lot of fruit salad on your backswing, you have to toss up into the stratosphere...and then hope you time it right.
- Serving, like all of tennis, is a leg sport, not an arm sport. Actually, it's a whole body sport. If you want more spin, power, safety, direction on your serve, get the legs, hips, shoulder turn, all of the parts working together.
- As Stan Smith noted, the wrist is the trigger. I'm talking about getting snap on the serve, which is the final link in the kinesthetic chain that gets power, spin, and all the other goodies on the serve. There are drills you can do to get more snap...like getting yourself into the back-scratching position, or whatever it's called these days, tossing, and trying to belt the serve down into the court as hard as possible...hard enough to bounce it over the fence is usually a good goal.
- Rhythm and sense of all the parts of the serve working together is definitely key. Another of my former coaches (Dave Hodge, former Men's Assistant at CU Boulder, current Men's Assistant at Stanford) gave me a great way to look at serving: The serve is the only stroke you hit that is not a response to the other player's stroke. Therefore, have an objective every time, even if it's "Okay, second serve, lots of kick and safety, straight down the middle." If your thought is "Hail Mary, full of grace, I hope this serve isn't a fault", guess what? You'll whap it right into the net. What he said was, make up a little video in your head of what you're going to do with the service motion and where that's going to take the ball into your opponent's service box. Take a deep breath, relax, and replay the video in real time. Works like a charm...