The single most important fix for your volley technique in tennis
If you are struggling with your volley, then there is a good chance that you have been doing one thing wrong, and that is the initial movement. What is the first thing you do when you see that the tennis ball approaches you either on your forehand or backhand side?
Most tennis coaches will tell their students that they should execute an "on-the-spot" turn to the right or left and to swing the racket back just a little. The next movement would then be a diagonal and forward step towards the ball. That is the way volley have been tought for decades - and it is completely wrong! If that is the way you have been doing it, read.
What's the problem with the technique described above?
First problem: After that first diagonal step, you will not be able to make another step before hitting the ball. Let's assume you are right-handed. You make one diagonal step with your left foot trying to hit a ball on your right side. At this point, the weight of your body will be on your left foot. Under ideal circumstances, your timing should be so that you hit the ball while making that step. Also, ideally the ball is within your reach (not too close and not too far away from your body). If that is the case, your volley should be ok.
But circumstances are almost never as ideal as that. Very often you will find that you made that diagonal step but the ball is slower than expected - you have to wait for the ball, and the forward momentum from the one step you made is lost. Even more often, you will find that the ball is out of your reach because your opponent has placed it more to your right. But with the weight of your body on your left foot already, it is impossible for you to make another step (let alone two) to bring you close enough to the ball to hit it.
Second problem: When you turn on the spot and swing your racket back at the same time, most of the time you will either swing back too far and not be able to bring the racket forward again (if the ball approaches faster than you thought). Your point of contact will be late (behind your body), which is the worst thing that can happen. Or, the ball approaches slower than you thought, and because you have only swung back your racket a little bit, you cannot swing back any more to add some speed and depth to your volley. Also, not ideal.
So what should you do?
When you see the ball coming to your right, your first reaction should be to make a short step to your right with your right foot! Ideally, your right foot should now be pointing approximately toward the net post. Do not swing your racket back at all. By executing this step, you have already turned your whole body to the side, and your racket is in position for a short blocking movement. The important part here is that you are a) in balance, ready to make another step (or even two); and b) your racket is in position to block or hit the ball in front of your body if needed.
At this point, you can see how fast your opponents shot is and whether the ball will be in your reach or not. And you are in a position to choose your next movement(s) depending on the quailty of that shot.
If the ball comes very fast, make a step with your left foot towards the ball. Do not swing back any more, just block it, while moving forward.
If the ball comes slower (meaning you want to add some speed to it), then swing back just enough to achieve that, but make sure you still have enough time to hit the ball in front of your body. Most importantly, you can stay on your right foot and time your final step toward the ball so as to put the weight of your body into the shot at the right moment.
And finally, the most important advantage of this technique: At the moment when you make that first step to your right, you will be able to make more steps in case the opponent has been able to place the ball very well. Already, with the two steps (right - left), you have increased your "reach" compared to the "left-foot-across" technique. But also, after opening to the right with your right foot, you are even able to make two or three more steps if necessary. That is because, after that first step, you still have a balanced stance, as opposed to the "left-foot-across" approach which leaves you committed to your position.
By using this technique, you will be able to reach balls that you were previously unable to. Your coverage of the court will have increased by at least half a meter to the left and right (if you make just two steps) or even a meter and a half (if you can make four steps). That is a huge improvement. Bear in mind that especially shorter players and players with relatively short arms benefit a lot from this technique. I am only 5'8'' and I learned to volley the old-fashioned way. I never felt comfortable at the net before I made this change.
Obviously, there is one caveat here: If the opponent's shot is well-placed and fast, you may not have the time for a right-left-right-left 4-step combination. But there is always enough time for two steps, believe me. Well, some balls are simply too good to make four steps - but those would have been even more out of reach with your old technique, right? And the more you practise this, the more often you will be surprised by your new ability to reach well-placed shots made by your opponents.
How to train this volley technique?
In order to acquire this technique, set up a training session with a friend. He does not have to be a tennis coach, but make sure that you bring at least 20 balls. Have player A in half-court position feeding slow balls to player B. Start out with forehand only, and focus on the one-two (right-left) rhythm. Then, do the same on the backhand (left-right). Then start practising with random shots to your forehand and backhand, again focusing on the one-two rhythm. Next, improve the speed of the incoming shots. Then, have your training partner feed you faster balls from the baseline. After 60-80 shots, player B feeds balls to player A.
Believe me, you will find that you can acquire this very quickly, and you will feel a lot more confident about your volleys in your next tennis match!