Hi,
Great question. Shadow play without the ball is often useful in these circumstances. Always imagine the ball, where you want to contact, and the timing of the shot.
If you want to practice making a good contact. You could try putting a ball on top of a bottle and brushing the ball off. Maybe weigh down the bottle somehow.
Also, you could some research on visualization/mental rehearsal. It can be really effective when you having got the option of playing. Perhaps we will put a video out on this in the future.
Happy training
Dan
Answer for Forehand topspin (practicing alone)
