Test camera, mic and link ten minutes early. Fix tech before the handshake, not during it.
Frame at eye level, simple background, light in front of you. They should see your face, not the ceiling.
Look at the lens when you greet and when you close. The rest of the time, a natural look at the screen is enough.
Mute notifications. A banner mid-argument kills the rhythm.
Keep a sheet with three examples. Not a novel. Just enough not to hunt for words.