Especially annoying are deer flies that bounce on your head, finally land on your skin, make a cross shaped incision and lap up your blood. Hateful creatures.
If you don't care how silly you look (and I don't), take a hard hat or a plastic bowl (blue is supposed to be an attractive color) and slather it with tanglefoot.
Since you are the bait the flies will come to visit but will never leave, wriggling around in their death throes.
I also find that a hand held bug zapper is especially useful, with a satisfying snap and the smell of burning bugs.
This female deer fly is never going to lay her eggs (stuck on flypaper)
Party like it is 2006! This novelty hard hat was perfect for this application.