Do your hair and makeup in the style that makes you feel comfortable and confident.
Wardrobe: Stay away from solid black or solid white, as it can tend to blend into the background. Try wearing vibrant solid colors -- everyone looks good in blue on camera.
Do not wear any shade of green if you are using a green screen.
Avoid wearing shirts with prominent logos (unless they are the logo of your university/company) to avoid any potential legal issues.
Avoid wearing big necklaces as they have a tendency to bump against the microphone. Jangly bracelets will also be picked up on the microphone if you are moving your hands around causing the bracelets to clink together.
Avoid tight patterns (like tiny stripes, polka dots, checks), as they can cause a “moire” (or buzzing) effect on the camera.