One thing I've tried with my super aggressive Roo that seems to work is flapping the sides of my flannel shirt at him. I noticed that before he attacks me, he always flaps his wings, so I started flapping my "wings" at him first. It actually helped, although I feel kinda silly doing it. The other important thing is to never let him know that you're afraid of him - don't back up, don't look away, etc. I have two roosters, and the "alpha" rooster has adopted me as one of his hens, so whenever the younger rooster charges me, the alpha rooster knocks him out of the air. I feel very loved.