Here is a simple 3 light setup. The pictures says it all but, I will explain it anyway. The main light is soften by the softbox. The two edge lights are .5 stop brighter that the main light. This creates dimension. This is what I call painting with light. 

Here is a photo I took at Papago Park in Phoenix, AZ. It was a fun place to shoot at.

This is image is considered a composition.