Couple of ways to avoid fights:
Do not get drunk or mix with drunk people.
Body language matters as much as anything.
When i was at college there was a spate of muggings. One of my mates actually got mugged 3 times.
I was a fairly nocturnal creature back then and used to go out looking for muggers.
Never found one. I guess they just used to see me coming and decide against it.
Used to have a mate who'd always wait in the student union till I walked back to the flats in stoke. He used to say it was because: 'I'm big and you look mean'.
Another of my mates had avery short temper and used to play rugby to get rid of his aggro. His house mates were all scared of him, I used to go round and deliberately wind him up
Went round there one day and he had a couple bandages on his hands.
Asked him how it happened and he went and got a stanley knife. Said he'd taken it off a mugger.
Asked what happened to the mugger: 'I ran his head into a tree'.