The key to controlling a rally in racquetball is to keep the center court position. Center court position is located 1 or 2 feet behind the 5 ft encroachment line. Pretend there is a very powerful magnet always pulling you to this spot on the court.
Keeping center court position is so important because any mishit shot by your opponent will pass through center court. And, any shot struck too hard or high will rebound off the back wall and come back to center court.
So after you have hit your shot, don’t stand there admiring it — move towards center court!