Everyone who knows me knows that I have trained in various martial arts for years
and over that time I've been in a few scuffles with people trying to be tough guys. However I always say to people that if the situation allows you to walk away from it then do so.
Walking away from a fight may look like a wimp's way out but at the end of the day you're not getting injured, you're not going to get hurt and you're not going to have to deal with any of the hassle from law enforcement either. However having said that sometimes it is completely unavoidable and action will have to be taken so that you survive.
If your arguing with a person remember to try and cool the situation down and calm everyone involved if this then doesn't work chances are that the other person will still be aggressive, at this point if their shoving or pushing you get into a fence position this position just means to put your weaker arm closer to them with your stronger arm behind at shoulder length. This fence position not only looks like your telling the person you don't want to fight but it's also useful if we want to land a strike.
From here I have a general rule, I will try and keep the person from me but if he pushes on to me at least twice then i'm going to strike, I can either do this with a punch or my favourite and open palm to the face followed by an elbow.