Hey Fabian, I think your overall technique is pretty strong here. I would say especially on the open ups that you need to take the ball a bit earlier with your timing, often it drips a bit low and it gives you more work to do to get spin and power into your shots. Also your weight is slightly on the back foot, it will really help if you can lean your body forward and get your weight finishing more forwards at the end of the shot. This will help the timing bit also the recovery for the next shot as well.
I do also think you could be a bit more relaxed in your arm during the shot and get a bit more rotation from your body and shoulders through the shot. I think these are the main areas to work on for now, but they are quite small things, overall the technique is good and just needs some work on these areas to help get to the next level. Any questions on this just let me know. Dan 🙂Â