Ian, from Essential Tennis, had some good tips for practicing against the wall:
Backboard or Wall Hitting Lesson
http://www.essentialtennis.com/video/2011/10/backboard-or-wall-hitting-lesson/
Hitting on the second bounce can allow you to better concentrate on perfect strokes, and better approximates your distance to the net for baseline rallies.
Hitting that target, and having goals for consecutive hits, can sharpen your focus.
But you can also use other stratagies.
One is to intentially put yourself in trouble, just like happens all the time on the tennis court.
Move in to take it earlier and earlier on the first bounce to mimic when you are being pressured, and to learn to hit it "on the rise". [With experience you can anticipate how high the ball will be bouncing from how fast it is coming in and where it is bouncing so you can time your stoke to hit it - hint: the ball will usually be low, so prepare to hit a low ball and start your stroke up accordingly.]
Practice half volleys - you're going to need to hit them in match play.
Practice volleys.
Practice coming out of your split step.
The wall is like the other player on the
double bounce practice, so split step when the ball hits the wall.
But with
single bounce practice
you are hitting it when your opponent would be! - (your spacing to the wall is only 1/2 the distance from where your opponent's ball would be crossing the net, with the other 1/2 distance when the ball is coming back to you!)
So you can get into of the habit of always moving out of a split step on the court by immediately recovering into a split step after hitting the ball, then moving out of a split step for your next shot. [This is especially true if you are hitting the ball hard, you won't have time to split step if you wait until the ball is coming off the wall.]
Don't fall into the bad habit on the wall of hitting only line drives without topspin. You can fall into this trap as the ball will come back faster, and be a better test of your ability to return harder hit balls. Plus, if you are a little low, the ball will still come back (and not stop in the net). But you need to continue to hit topspin on your drives to have a stroke that will not result in too many unforced errors when you return to the court. Remember to practice hitting "low to high".
Practice serving against the wall. You shouldn't have to chase too many balls if you simulate a T serve from the ad court.
Practice playing points against the wall. Return your own serves, hit some groundstrokes until you get a "short ball" to slice down the line, and come in for the volley. Then hit volleys until either you or the wall wins the point. [But be forewarned - it's hard to beat the wall. :roll:]
Good luck!