Your best bet is to learn how lights work in general. Light sets don't always supply what you need. Sometimes it's better to make what you need ;).

I use Advanced Light and Camera guides from RDNA to place my lights and actually SEE the area of influence each light has. Helps a lot :). I've fiddled and fiddled with a light only to find that the distance wasn't enough to reach the object I was trying to light. Advanced Light and Camera guides helps with that.

Laurie