Finally figured it out once and for all. More or less.

Hit with two hands for both backhand and forehand. Hit flat. Use an oversized racquet which is heavy and strung loose so you can swing smooth and slow and still hit hard. Preferably extra long. Hit the ball out in front of you. Use a topspin grip in order to hit it out in front of you. So on the right side, both base thumb knuckles on bevel two and on the left both base thumb knuckles on bevel 8.