Hand feed drills with a coach, pushing you back and paying close attention on how you move, feet positioning and staying behind the ball at all times.
http://www.youtube.com/watch?v=SlhvLQCVOak
Here is one example of a drill that can be done, even though he feeds it with a racket, this can be fed with hands as well or the way he does it, it doesn't matter. The reason its better to do hand feeds in this situation in my opinion is the coach has complete control over the players movements and can manipulate them exactly how he wants them. Plus, the ball has no pace, so the player has to work harder to generate pace, thus if you're sloppy, lazy, sluggish or out of position, the ball is going nowhere.