Pepper spray
Yep... it can have serius side effects and should be used with caution and only as a last resort to trying to be polite and talk your way out.
Give up your purse or wallet... no material item is work injury or death.
But if you have to draw whatever weapon you may carry, remember: Do so *only* if you plan to follow through and use it. *Don't* use it as a threat. *Don't wave it around to make a point.
Be physically and mentally capable of using it or don't carry it. I can give a false sense of security and get you into even more trouble.
And always be aware of your surroundings. It's called 'tactical awareness' and is your most important weapon.
If you do own pepper spray and find you need to use it, aim for the center of the face. Put them down on the ground... now ... and then run like hell to a safe zone [open store, a crowd of people, things like that] and call the police.
If you own a gun and find you have hit your last resort - it's that our your opponant will seriously harm/kill you - aim for the center of mass [chest/belly], don't try to 'wing them'. Keep firing until they go down. Do *not* approach them. Do call or have someone call the police for you. Retain your weapon and do not leave the scene. When the police arive, lay the gun at your feet and raise your hands so they can tell you're not carrying.
And be ready for the possibility the police will also want to take you downtown to sort things out.
Remember, nothing material is worth a life. A life, however, is.