Lens Hoods

[Sunny Chung]

I have a lens hood, buy I hardly ever use it.  Whenever I do use it, I
can never tell the difference in my pictures.  What is the best
situation to use hoods in, and how do get the most out of this
accessory.  So far, I know NOT to use it with flash and that it can
make my lens look bigger to non-camera people, but haven't really
figured out its use.