Originally Posted by sjoerdklarenbeek
Most has been said already. What strikes me is the way you bend over sideways over your right hip towards the ball. That is not very efficient for generating power. I think maybe you should use more upper body rotation. Be a bit more Federer-like: be loose, let natural rotations and swings of your body parts generate power, and "look the ball onto the strings". Easier said than done. Perhaps it helps if you try to imagine that you can hit the ball hard without using muscle power.
Did you see FailBetter's post #32?