Position The Main Subject. Always consider putting the primary subject in the center of the frame. If there is a definite left, right, front or back to the subject it might be shifted to the right or left, but if, for example, it is a round flower vase (no right or left) possibly it had better be in the center of the frame if it is to be the only thing in the shot. As soon as you put it to one position you draw attention away from the vase and into the empty space on the other side of the frame. If nothing will ever be introduced in this space, and then your audience is left wondering what was supposed to be there when the shot ends. Admittedly, there could be many reasons for ignoring this advice, but be sure you have a definite reason.
Set The Headroom. The term headroom refers to the distance between the top of your subject (like a person’s head) and the top of the frame. When it is a human head, it’s disturbing if the top of the head is “cut off” by the top of the frame. As you tighten the shot from a medium shot to a close up to an extreme close, up you will eventually have to sacrifice the top of the head, but in a very close shot that’s acceptable. It’s better composition to keep the chin and loose the top of the head. A good way to think about this is to always have the person’s eyes on the (imaginary) line that defines the top third of the frame.
In your imagination as you view your shot in the viewfinder, divide it into thirds both vertically and horizontally. The most interesting or powerful areas in the frame are where the vertical and horizontal lines intersect. So, for example, if you’re taking a shot of a small wooden church on a distant hill out in the country, you might want to place the church on one of the two intersection points in the top third of the frame. It’ll be a more interesting shot than just centering the church, especially if you see the church in profile (that gives it a sense of back and front).
Set The Lead Room. Lead room refers to the space you should put in front of a subject that is looking or moving left to right – or right to left. This can be a person standing still in profile speaking to someone who is off camera, or a car that’s moving as you pan or track with it. It’s common to put more lead room in front of the subject, but not so much that the subject’s back is against the frame behind it. The space in front is more important to the viewer than the space behind.
Check The Periphery. The periphery is the part of the shot that is right against the boundaries of the frame. After you’ve framed your shot, but before you roll, you should quickly check the frame all the way around. After your eye has traveled 360 degrees, you should search within the frame as well. It’s sometimes amazing what you find. Often it’ll be things that should not be there during your shot (electrical cords from your lighting, a shadow of the boom mic. or maybe even a person who you don’t want in the shot). A periphery check is very important.