Players are often amazed at how accurate a top player can place his shots. This is an important skill to develop since the large majority of the time there are only three places you want to place your shots - wide forehand, wide backhand, and the opponent's middle (midway between forehand and backhand - see Attacking the Middle, where this is explained). When your shot goes elsewhere (i.e. toward the middle of the forehand or backhand sides) you give your opponent a much easier shot, where he doesn't even have to move much. And yet most players let their shots drift out of these three spots, and lose many matches as a result. So how can you learn to hit these shots accurately?
Obviously you can go out to the table and just practice relentlessly, aiming for these three shots. But there's a shortcut that'll help before you do all this relentless practice. Go to the backhand side of your table, stick your racket out as if you were doing a backhand block, and aim it crosscourt, wide to the opponent's backhand (if you are both righties). Make sure your racket is aimed right at the wide corner, or even slightly outside the corner. Keep holding the racket out there until you have literally memorized the feel of holding the racket in this position, so that in a game situation, you'll go into this position and hit the shot right to that spot.
Now repeat, except now aim it down the line. Again, memorize the feel of holding the racket in that position. Then repeat one more time, this time aiming at where the opponent's middle would be. (Alas, you actually have to do this twice, for a righty and lefty opponent, since the righty's middle will be a bit to the right of the midline, the lefty to the left.)
Once you've memorized the feel of the racket aiming where you want it to go, imagine the ball going to your left, and step there with your left foot, and imagine keeping the racket angle so that it still aims where you want it to go. Now imagine a ball going to your right, and step there with your right foot, and again imagine keeping the racket angle so that it still aims where you want it to go. Moving is no excuse for losing ball control - the ball will still go wherever you aim your racket.
Now repeat all of the above with your forehand!
Here are some complications to be aware of.
Once you get into the habit of aiming the racket by learning the feel of it, you'll be able to accurately hit shots to the corners and middle at will, against any incoming shot, and from all parts of the table. This will put tremendous pressure on opponents since you won't be giving them many easy shots - and this relentless ball placement will pay off in many wins!