Use a fixed camera shot.

Consider using a tripod to hold your phone/camera.

Make sure to position your phone/camera to capture as much of your body as possible while still being able to make out facial expressions.

Make sure the image is in focus.

If using a pre-recorded track, ensure we can hear your voice clearly over the recording.

Practice your piece in the space you plan to record.

Record your practice session and check for additional sound and lighting issues.

Sound: Make sure the acoustics in the room are suitable for a recording.

Lighting: Make sure the room is well-lit. Judges should be able to see your face clearly. Avoid glares and overexposure.

Do a test run, watch the video back, and adjust as necessary.