Video Advice
Never handhold if you can possibly avoid it. Use a tripod or a firm surface.
If you zoom and pan while you film, do it sllloooooooowwwwwwllllyyyy.
Try never to use the on-camera mike. If you do, remember that everything closer to the mike (e.g., YOU) will be louder.
Pay attention to the background!
After I posted this, I found this which repeats much of what I’ve said, but says more.