Rule Number One is to always get on the same level as your subject. Bend down and hold the camera at the subjects eye level or just their level if they don't have eyes. This rule makes the picture more intimate and you get a sharper image. It also allows you to get a better background in the shot.
Rule Number Two is to use a plain background. You don't want a "cluttered background" because it's distracting. A plain background emphasizes the subject. To get a plain background position yourself for the best angle.
Make sure to check the area behind the subject and lookout for trees or poles that might look like they are sticking out of your subject when the picture is taken. Remember, pictures aren't in 3-D. You can't tell if there is any distance between your subject and the tree or pole or if it just growing out of their head.
These are only the first two rules. More will be coming soon!