In this video, Malia Bailey provides an excellent guide to the forehand and backhand grips and stroke techniques.
In general, remember that the wind-up and turn of the hips and shoulders is the main source energy in your forehand or backhand racquetball strokes.
Also, aim for a smooth, relaxed stroke. You don’t want any tension in your upper body. Allow your stroke to accelerate after you hit the ball, and then follow-through completely until you are facing the front wall. Fluid strokes are more efficient and won’t tire you out during a match.