1. ADJUST TO A SLICE GRIP
To hit an effective slice serve, you’ve got to start with the right grip. For many players, holding the racquet with a Continental grip allows them to put adequate slice on the ball. If this works for you, then stick with it. However, if you have trouble generating enough spin this way, I recommend adjusting your hand slightly beyond the Continental toward a backhand grip. This “slice grip” makes it easier for the edge of the racquet to lead the way toward contact, creating more brushing action against the side of the ball, and consequently extra slice.

2. USE THE NET POST TO ALIGN YOUR BODY
To properly coordinate your body, toss, and swing for a slice serve, the two net posts on the outside of the court can function as helpful points of reference. Establish a serving stance where your body is aligned with and facing the net post on the right side of the court (opposite for lefties). Now, turn your upper body so your shoulders are in a line perpendicular to the net. This alignment will facilitate and amplify the effectiveness of the rest of your service motion.

3. ACCURATELY PLACE THE SERVICE TOSS
Have your arm fully extended but relaxed as you begin your tossing motion. Line up your tossing arm with the net post and lift the ball along that line. You want to position the ball as though it were directly above the net post , but still well within your reach. The contact point for the slice is typically lower than what you ideally want for a hard flat serve. This will allow you to brush the outside part of the ball to better apply an upward sidespin to the serve.

4. THROW THE EDGE OF THE RACQUET AT THE BALL
To generate good slice, you have to swing as if you were intentionally trying to hit the ball with the side of the frame. Initially it may feel like you’re going to shank the ball off the edge of the racquet, but after a few tries you should get results.

Try to focus on the point of contact to avoid mishits, and swing upward to create the slice spin. Most players make the mistake of trying to cut straight across the ball and spin it down into the court. You should actually feel like you’re spinning the ball up off your strings. This creates an action on the ball that’s part topspin but mostly sidespin. Both are necessary: The sidespin puts a curve on the ball and topspin brings it down into the court.

Again, use the net post as a guide as you accelerate the racquet high above it to lightly brush up and across the outer side of the ball. When first experimenting, make an effort to graze the fuzz of the ball without making too much direct impact. As you get comfortable, start hitting more of the ball to add pace to the serve.

5. MAINTAIN YOUR FORM AND FOLLOW THROUGH
To maximize spin production you need racquet-head speed. That means the head of the racquet should travel much faster than the handle into contact. Like throwing a hatchet where the blade edge leads as it flips end over end, you want the leading edge of the racquet head to travel at top speed. The key to achieving this is to keep your wrist as relaxed as possible in the motion and avoid forcing the racquet head to snap.

With this emphasis on racquet-head speed, there’s a chance that your upper body may fold over or that you’ll swing too close to your chest. Make sure your follow-through is in line with—your new best friend—the net post. It may feel awkward at first to swing in the direction of the post to slice the ball. You must remember though, when you lead with the edge of the racquet, it will contact the ball on a severe angle. That, combined with the right-to-left spinning movement of the slice (opposite for lefties) will take your serve to the desired target. It’s like learning to throw a curveball in baseball. You first must overcome the fear of throwing the ball to the right of the catcher’s mitt and trust that the spin will take the ball into the strike zone. In tennis, the ball may start to the right, but after it hits the target it will continue to tail away from your opponent, creating a wicked slice serve.