Simplify your frame. Think about where everything is going to be. People coming in and out of the frame can create movement that may cause confusion. A lot of auto-focus cameras can't focus properly if you are too close to your subject. Five or six feet away is a good distance.
Good lighting is essential.
Try to light your scene from the front. Try shooting outside if possible. Use the fastest record speed. This will insure the best video quality. Record in a quiet place.