Nebulustrix has some good ideas.
I'd also add situational awareness. It's difficult to describe, but sometimes there are visual cues / body language people have that indicate you want to keep distance from them.
Figure out the safest places to park your car, safest routes to and from work/store/school, alternate routes, where to run if something happens. Stay clear of bars and similar establishments. Bad people hang around those sometimes and other times, good people that are drunk hang out there.
I also endorse the idea of mace or pepper spray. (Mace isn't considered legal in some areas.) You can get key-ring size cans of pepper spray that are inexpensive.
Understand what you have on you that might serve as a weapon (though disengaging/ running is preferable to fighting) like shoes, books, bags, keys, fingers, etc.