Most people have heard of The Rule of Thirds. Divide the screen into an imaginary grid of 2 vertical lines and 2 horizontal lines equally spaced. This gives you 3 sections in each direction, or 9 sections total. The places where these lines intersect is the best place to frame the most important part of the picture. If you are shooting a person, their eyes should be placed at one of the top intersections of lines. A horizon should be at the top or bottom line. Most people don’t break this rule, but if you do decide to center the subject, have a good reason.
For more about Shot Composition (such as head room, nose room, and cropping), get my eBook How to Shoot Video Like a Pro: 12 Tips For Using the Camera You Have. Send an email with your request to email@example.com