Wow, so much to read and comment on! Slow moment at work, so I am going to throw in my two cents worth.
Lots of good advice here. Personally, I always look a potential attacker in the eyes. The key here is to maintain proper distance so you can see his arms and hands while maintaining a neutral gaze. Any closer than that, and I would consider it a provocation. But, I take medication for that...
Seriously, I do!
I'll be, oh, 39 at the end of this month, and I have been in only one fight in my adult life, which happened at a bar, and I was totally blitzed. I tried to step the testosterone level of the encounter down with some sensible words, but that didn't work.
Anyway, I was always picked on while growing up because I was the smart, nerdy, small kid. Well, I started training in karate at 17, and weight lifting at 19. As a result, I got pretty honed for fighting, BUT, I never did get into a conflict because of the way I presented myself. Believe me, I had lots of opportunity. I usually de-escalated the situation by simply being ready for it. "Back in the day" I had a social-anxiety disorder, where I suppose I was feaful of confrontations, but when the fight or flight response kicked in, I was always ready for the fight portion. I would never start the confrontation, but boy, was I ready to participate in it. I mean really ready. It was sort of thing where my body language would say "I don't want to fight you, but if you want to fight anyway, I will not only defend myself, but I will attack you back. I will hurt you." It was always that way; the fear response would kick in, adrenaline would flood my system, breathing would get more rapid, I would aquire that look on my face that was neither aggressive nor frightened, more of an expectant look. And, I would watch the would-be attacker as if I expected him to do something. That alone has gotten me out of numerous encounters. Maybe the BG was thinking "this dude is freaking nuts, uh, probably not worth it".
But, like I said, I am on medication that takes care of my anger and aggression issues. But, I did learn some things out of all this. Most importantly, I think, is attitude. Do not appear to be a victim. To help with this, one posture which works is leaning forward with your head a little. Really, this is important in many aspects of life, including things like sales. A person who carries himself/herself with their head slightly forward signifies someone who is confident, capable of handling themselves, someone who moves with authority into a situation. People who carry themselves with their heads back are often viewed to be in a retreating situation already, unsure of themselves, weak.
Not always 100% true, but if you were an attacker, would you be more likely to attack someone who is leaning slightly towards you, hands half-clenched at their sides, or someone with their head leaning back, showing you their palms? It goes back to our primitive responses.
If you look like a good victim, you probably are one. The meager looking old man who turns into the ex-navyseal martial arts master who kicks the collective butts of an attacking group only happens in the movies.
Nothing works all the time, though. The best way to avoid an attack is not to be there in the first place.
Wow, I am babbling now. Back to work.