Microphones are mainly omni-directional which means they pick up sounds from all sides, unlike your ears. What may not sound distracting to you, can ruin a recording – a radio in the background, a dog barking, vibrating phones. Noisy fridges seem to be a particular issue!
Looking down into a camera means you are being filmed up your nose. I speak for myself but this isn’t usually someone’s best feature!
If it’s an important message, what are you wearing? How’s your hair? Are you shiny? Contrasting patterns and pinstripes don’t look good on camera so again, try to keep things simple.
Try to fill your frame with about 20% headroom at the top. That’ll give the editor working on the piece room to move the image around if need be.