The trajectory of the slingshot is to the right. Some people say that we need to adjust our forehand. I tried, but it didn't change much. How to control the trajectory to the left and right?

Fine-tune the back of the right hand to the right and the back of the left hand to the left. If you aim horizontally with your eyes, you will see a straight line of epithelial tendon facing the target. More practice will form muscle memory, and you can play accurately without sticking to your face for a long time.

That's how I practice. I hang an iron nail or 10 meter to hit the side of an iron sheet, so that the problem of left and right deviation is solved. Generally, you can play very well after practicing hard for about a month.

The back hand is unchanged, and the front hand is slightly adjusted.

Forehand unchanged, backhand slightly adjusted.

This adjustment must not be too big. This is a slight difference.