I usually wear a ball cap with a short brim, or a regular ball cap that I slide back on my head when I get ready to shoot. I've got a boonie with a really short brim from Bass Pro that I wear a lot too. Also, since I'm well over 50, I'm legally allowed to wear a fedora hat and NOT TAKE ANY CRAP FOR IT!
A friend gave me a camo ivy cap for a joke, but it's surprizingly functional for bowhunting. Short bill and stays out of the bowstring's way. It looks a bit dorky but, again, I'm over 50 and don't give a crap.[8D]