Something a lot of people bypass but to me is invaluable training.
CONFLICT RESOLUTION!! Become an expert in conflict resolution. Not only will it improve personal relationships it will help you with irate strangers as well. There is a lot of free training around for social workers, correction offices, police officers. Some classes may cost ya $50 for some material. I keep a file folder full of em. I get written "testimonials" about how I did in the class from the instructors. It's not a magic bullet and will not get you out of every dangerous or potentially dangerous situation. If the worst should ever happen and you have to use a weapon you have a pile paper to cover your butt with.