garage lighting question

I have a 24X24 shop with 10' ceiling that I have 6 4' flourescent fixtures. I have them on 3 separate switches so that I only light up that part(s) of the shop I am working on.
A couple other pointers. Paint the walls and ceiling, it will help reflect the light and make it brighter inside.
I live in Georgia and most of the time my 16' garage door is open. Position the lights that would be covered up by the door so that they are over the door windows. It is not as good as when the door is shut, but still very good.
C