A great serve starts with the perfect toss. Ace yours with the help of Sports Illustrated senior editor Richard O'Brien, author of The Ultimate Sports Handbook.

Toss the ball—with your arm outto the side of your body—directly above your hitting shoulder. This will force your shoulders to rotate and help initiate power.

Throw the ball slightly higher than where your racquet will strike it. Throwing too low limits your power.

Contact the ball at the highest point in your swing, snapping your wrist forward.

Go ahead and grunt—that is, exhale strongly the moment the racquet connects with the ball. Holding your breath only builds tension and robs your swing of power.

Reprinted from The Ultimate Sports Handbook by Richard O'Brien, June 2005. Permission granted by Quirk Books, Philadelphia, PA.

See Also:The Tennis WorkoutMardy FishSerena Williams