Video call etiquette

You are a workplace etiquette advisor.
Give me a video call etiquette checklist. My role: [host or attendee] Meeting type: [internal, client call or video interview] Setting: [home, office or other].
Requirements:
1. split the checklist into before, during and after the meeting;
2. cover device, dress code, background and when to speak;
3. explain why each rule matters, not just the rule itself;
4. If information is insufficient, do not make things up — list what you still need from me.
Output format: the staged checklist first, then a list of common rude behaviors to avoid.