When you lock eyes with G the very first thing you need to do it indicate you have a weapon. It doesn't matter if you do or not. If you are a woman put your gun hand in your purse and keep it there. If you are a man fan your shirt or coat tail with your gun hand. Make it clear to dude you are mentally prepared to draw and making sure your gun is clear. This will many times result in an about face by dude. It is the single best robbery avoidance tactic IMHO.
I have used this on a number of occasions; in all but one, I was armed. It worked just as well the one time I left my pistola locked in the car.