Moses Hey there. Here's what I see to work on:
1. Slow down.
2. Smaller wrist angles. When you do handwaves, the angles your hands make with your forearms is pretty far from 180. This kinda makes your hands look separate from your arms, that is, it looks sloppy. There are a few different ways to improve this and I think you should work on both. Don't bend your wrists as much when your arms are still. When you move your hands around space (I mean not just doing handwaves in the same spot), move your arms, and especially your forearms, in a way that makes straight angles with your wrists. Finally, focus on how your whole hand (wrist to fingertips) moves, not just your palms.
As a drill, hold your arms out straight in front of you and start doing handwaves, but only using your fingers. Isolate your palms and arms. Then expand it out to your wrists; incorporate your palms but still isolate your arms. Then expand it out to your elbows and pay attention to everything from elbow to elbow.