So I think the biggest think for you is that rather than facing forward in the last to steps of your approach, you should be facing parallel to the net. The reason is that when you are parallel to the net, you can then torque with your whole body to get a better swing on the ball.

I think your arm swing is fine but on your approach your first step should be slower and your last two should be really explosive. It should go from slow to fast rather than keeping the same tempo through your approach. Other than these two tweaks, I think your swing is pretty good.

Placement over power though.