The self-defense continuum always begins with avoidance. Walk/run away from a violent situation or try to talk your way out of it if at all possible. I live in a very low crime area, but sometimes have to work in high crime areas. Another part of avoidance is attitude. I'm not talking about being a bada$$, but having an alert attitude, head up, observant of your surroundings. Acknowledge people as they approach you. Sometimes, by recognizing an approaching person who may be an assailant, you remove their element of surprise or put them off balance and can avoid a situation. When they know that you are looking, things change.
If you look like a victim and act like a victim, soon enough, you will be one.