Location
Find a location with little background noise. Avoid areas with lots of echoes.
Choose a non-distracting background. Avoid windows, people in the background, etc.
Make sure your location is well-lit with natural sunlight or plenty of indoor lighting.
Lighting
If shooting indoors, position yourself so the windows are facing you and avoid overhead lighting.
Make sure your face is evenly lit indoors. If you need additional light, place a lamp in front of your face.
If you are shooting outdoors, position yourself with the sun high in the sky and behind the camera, or shoot in the shade.
Avoid having your light source in back you to eliminate being backlit.
Camera setup
Whether you are using a mobile device, desktop/laptop computer with a webcam, or any type of camera, make sure to check your camera settings and you are capturing one of the following formats: 720p or 1080p.
Use a tripod or steady surface to avoid shaky footage and to keep well framed.
Position your camera 2-4 feet from you to provide good framing and best audio quality, especially from devices with built-in microphones.
Position your camera at eye level, avoiding angles where the camera lens is looking up or down on you.
If shooting with a mobile device, be sure to shoot horizontally, not vertically. Avoid portrait mode and use landscape mode.
On-Camera Presence
Look directly at the camera at all times.
Keep your hand movements/gestures to a minimum.
Stand/sit up straight, avoid seats with wheels/swivels, overstuffed cushions, or squeaky screws.
Avoid clothing with colors that blend in with your background, accessories that make noise.
Additional tips
Do a short recording test to make sure you can see and hear yourself clearly.
Begin and end your recording with a brief moment of silence to allow room for any editing that may be needed.