Focus on the mechanics of the stroke from the feet upwards. The bat is at the end of a chain of movements requiring good use of the legs, flank and elbow. Good timing of the ball is needed to develop power and spin.
This clip shows use of the wrist either a straight wrist or with a relaxed wrist to add spin and speed.
Learn the mechanics of each stroke to aid shot selection.
Here is a link summarising basic forehand techniques.