2. Use a plain background

A plain background shows off the subject you are photographing. When you look through the camera viewfinder, force yourself to study the area surrounding your subject. Make sure no poles grow from the head of your favorite niece and that no cars seem to dangle from her ears.

Right picture is Distracting background.
Left picture is better one.

1. Look your subject in the eye

Direct eye contact can be as engaging in a picture as it is in real life. When taking a picture of someone, hold the camera at the person's eye level to unleash the power of those magnetic gazes and mesmerizing smiles. For children, that means stooping to their level. And your subject need not always stare at the camera.

All by itself that eye level angle will create a personal and inviting feeling that pulls you into the picture

Right picture is too high.
Left picture is better one.