Tennis tips that worked for me

I've been playing tennis for years, and received coaching at various times from various coaches. Tennis coaching can be like a series of tips aimed at a particular stroke. For example, when I serve, the coach says "move your toss a bit to the right," or when I hit a forehand, he says "make contact with the ball farther out in front." Naturally I forget all this coaching when I'm playing recreationally, but occasionally, when I get particularly frustrated with a stroke that's not working (usually my backhand), I go through my mental checklist of tips and try to remind myself to take all that coaching advice. Here's what has given me results in the past.

General Ground Strokes

• Your first move should be to turn your shoulders and bring your racket back. That should be automatic. Then think about getting to the ball and swinging through it.
• Hit through three balls. Stand in the ground stroke position and place a ball on the court approximately where you would make contact. But instead of hitting just that one ball, think about hitting through three balls stacked closely together. This will make you hit through the one ball and hit out in front, and provides power and depth.
• Open your hips to the ball before you make contact. The rotation should come first from your hips, then your should turn, then your arm, in that order.
• Point the racket head behind you. When your racket is coiled behind you, it should be parallel to the sidelines, not the net. The butt of the racket handle should be pointed at the ball, and should stay that way as long as possible. That will keep the racket head way behind your fists. If you keep that position, it will force you hit the ball way out in front, which is what you want to do anyway. The alternative--what you should not do--is allow the racket to snap around, and roll over your wrists. Keep your wrists in front of the racket. They lead. 

Two-Handed Backhand

• Keep your feet planted, and hit off your back foot. Sometimes I fall back into a bad habit of allowing one or both feet to stutter right as I'm hitting the shot. Sometimes this takes the form of one of my feet actually going back. Instead, keep your feet planted (if you can get to the ball in time), and concentrate on leaning into the shot with your weight on your back foot. This will stabilize your lower body and allow you to hit smoothly through the shot.
  
• Keep the racket head up like a baseball bat as you move from ready position to the fully rotated position. This will cause the racket head to move in a large arc.
• Drop the racket head toward the ground on the back-swing instead of keeping it cocked upright like a baseball bat.
• Bend your knees. Your body is a tennis-ball hitting machine, but you have to position it at the proper height. So if the ball is low, lower the hitting machine appropriately. And by the way, the ball is almost always low.
• Make contact out in front. This will straighten your non-dominant arm. Try hitting a super simple two-handed backhand: Hold the racket out in front of your body, use a very very short back swing, watch the ball all the way into the racket, make contact, and swing to a follow-through over the shoulder. When you're comfortable doing this, gradually increase the back swing.
• Swing from inside to outside. Your racket should move not only from next to you to out in front of you (back to front), but from close to you to farther from you (right to left if you're left-handed). Imagine hitting a ball suspended over the center mark of the baseline, and painted on that center mark is an X with the two strokes pointing toward the net posts. As you hit through the ball, your racket should follow the stroke away from your body and out towards the net post--inside to outside.
• Use the replacement step if needed. When pulled out wide, first plant your outside/back(/left) foot before taking the swing. Then swing through the ball, and as you follow through hop over so your right foot lands where your planted left foot was. E.g., step on the sideline with your left foot, take the swing, and on the follow through your right foot lands on the sideline.
• Don't use an overly extreme grip. The racket face should be somewhat open when you strike the ball, and the contact point should not be extended too far out in front. Make contact closer to the body.

One-Handed Slice Backhand

• Start with the racket head cocked behind your neck. Your upper arm, lower arm, and racket should form three sides of a box, with your head in the middle. 
• When you chop into the ball, your racket arm moves forward into the court. Your other arm should be moving in the opposite direction, so you're spreading out your arms as you make the shot.
• Don't necessarily try for a lot of backspin. Instead, you can also hit a low slice backhand with side spin, which is usually called "inside out." Backspin is not necessarily the goal; inside-out is okay too.
• Keep your non-dominant hand on the racket as long as possible. This stabilizes the racket head before making contact.

Serve

• Watch the ball as you toss it; keep your eyes on it as long as possible. That will keep your arm up longer, and it will keep your head up longer (keep your chin up too). You don't want to drop your arm or your head too soon. That will just rob you of power.
• Keep your feet planted. I serve like Sampras (uh huh) in that I start with my feet shoulder width apart, and I don't move them. This is in contrast to the perhaps more popular "pivot" technique of moving the back foot up next to the front during the service motion. For me, the Sampras/Federer style is simple, and less can go wrong. (Fewer moving parts, I suppose.) But when I do this, I have to remember to keep my feet absolutely planted. I have a tendency to make a stutter step with my first foot, which robs all power from the shot. Instead of the power coming upwards from the legs as it should, it instead must come from the arm. This is a great way to strain your shoulder, which I did.
• Hit the second serve out in front too. Some people think the first serve toss should go out in front for power, and the second serve toss should go behind you for maximum top spin. Not so; both tosses should be out in front. If your second serve toss goes behind your head, you'll get no penetration from the shot.  Update: Tony Delario says this is wrong. The second serve toss should not be out in front, but should land on the back of your neck.
• Hit the second serve at the 7 o'clock position. By striking the ball profile at the 7 o'clock position on the second serve, you get under it and provide the needed top spin.
• Strive for the Power X. The X is formed when your tossing arm gets pulled down and your racket arm crosses in front of it on the follow through.
• Don't over-rotate. Your hips and shoulders should not rotate fully into the court after the serve. Kicking your back foot up and holding it there after the serve will prevent this over-rotation from occurring.

Return of Serve

• Don't take a big back swing. If the ball is coming in fast and you take the racket back far, you're probably going to miss your shot. Instead, think about taking a very short backswing and punching the ball back with a simple stroke.
• Watch the ball toss during your opponent's service motion. This is a good way to make sure you track the ball all the way into your racket--start watching the ball even as your opponent is tossing it.

Forehand

• Keep your feet planted. This is just like the serve point, above. During my forehand, I would sometimes allow my front feet to take a quick extra step as I was hitting the ball. If instead I keep that foot planted, then my body properly coils and I get a smoother, more powerful and more controlled shot. Don't let your feet dance around while you're in the middle of the stroke. Get to the ball, plant, and hit. This doesn't mean you can't be running while hitting. It just means that you hit while your foot is planted and your body is steady and moving in towards the net.

Volley

• Watch the ball until it hits your racket strings. Makes a world of difference. This goes for all shots. Watch the ball. Make it your whole world.
• Your first move should be to lay your racket head backward. This allows you to get under the ball and provides the backspin.

Overhead

• Run, don't shuffle. When in the overhead position, I found myself with a tendency to shuffle backwards. That's unnecessary. Just cross your feet and run like a man.