1 - If using a phone, make sure to have it horizontal and placed in a stable holder.
2 - Go to the video settings and click HD if applicable. (Show off your pro fit)
3 - Try to bring your camera closer to eye level. (Looking down may look dominating)
4 - Room lighting should be in front of you or off to the side. (Glare is not a good look)
5 - When possible mute your mic, they can hear all your noises.
6 - Using headphones will help eliminated feedback through your mic.
7 - Test your audio/video before a meeting, video chat with a friend and ask them questions.
8 - You don't want to show everyone how you eat.
9 - Excuse yourself before picking your nose. (Stop your video feed)
10 - Tell everyone at home you are having a video chat. (No surprise video bombs)