Ceiling Drills
I like to start my practice sessions with ceiling drills...it's a nice and easy way to warm-up your shoulder and swing. I usually start by hitting 10 forehand and backhand ceiling shots...they must carry into the far backcourt (ideally, a celing shot should fall 5' before the backwall) to count and I must hit 10 shots in a row or I have to start over.
Then I'll do 10 cross-over/down-the-line (DTL) ceiling shots. I'll start with a backhand or forehand DTL ceiling shot, then hit a cross-court ceiling shot...move over to the other side of the court and hit a DTL and then another cross-over, etc...until I've hit 10 successful cross-over ceiling shots (and DTL shots).
Depending on what I may be working on that day, I will usually repeat this routine 2-3 more times during the drill session...particularly after some anaerobic drills such as "wrist flicks" from the service zone.
One secret toward hitting a good ceiling ball is to get under it well before you hit the ball. In other words, do not be lazy in getting into position to hit the ceiling shot. I often see people sluggishly getting into position because they think they have all day since the ball is going so slow...they get into position just as the ball is coming down and don't have enough time to get set for the shot (feet planted, racquet back, stepping forward into the shot). This is true for any shot, it's just that everyone thinks they have all day to get to a ceiling ball.
Too often the ceiling game is neglected. Players misunderstand that playing aggressively means you must never hit a ceiling shot. There's a fine line between playing aggressively and playing outside your limits...you should always be able to count on your ceiling game to outposition your opponent and put you in an offensive position.