Interesting topic. As a police officer I spend much of my life getting mean-mugged by idiots, and it isn't something I get too worked up about. If they're acting stupid and not getting to the point of making me feel like I'm threatened, I usually just pretend they aren't even there, or laugh them off in a way that probably suggests that I think they're pathetic.
But, if the same hood rat pushes the issue more, and overtly challenges my safety, I think I'm more than capable of standing my ground, and I have enough experience and carry myself with enough command presence to make it evident that I'm not going to run from a fight. In nature, just as in the civilized world, predators look for easy prey, and they rarely challenge another predator. Showing them a bit of bored disinterest is fine in my eyes, but I don't ever demonstrate weakness around that type of fool.
Again, avoidance is the best course of action, but I'll always believe that it is better to fight than to be victimized. Staring me down means very little, and generally indicates that person's own insecurities, and their need to feel big and bad. But, if staring me down is a prelude to a physical confrontation, then we're going to have other issues to address in short order.
When I first came on the job as a law enforcement officer I was working in a particularly violent district. At that time I was a bit younger, plenty scrappy, and more than willing to tussle with trouble... But I also weighed in at a mere 155-160 lbs. I found more often than not that I would be the first target of verbal aggression when I was surrounded by cover officers who often tipped the scales at over 200lbs (again, criminals are looking for what they believe is the "easier" mark). But, being in that position taught me how to handle violence more readily, and gave me a case study in the subtle nuances of human stupidity. Since my job is one where avoiding the fight is not always possible or practical, I soon learned that most of these fools would quickly back down when they realized that you were more than willing to engage them in whatever conflict they had envisioned!
These days I'm trained up to 185 lbs, and I get less physical attention from subjects on the street
But, law enforcement work is different than going grocery shopping on my own time. In uniform I stand out, and everyone knows what my job is, and why I'm there. The criminals know who they are, and they don't like the cops. Furthermore, the criminals know that I'm going to pursue them when they screw up, which sometimes makes them a bit edgy with me. Conversely, when I'm shopping at the local grocery store on my time I blend in with the public. Most criminals don't have an agenda with me, and I'm not looking for a reason to pursue them during my down time. As such, I'm less inclined to engage them in a visual urination match in those cases! And, honestly, I don't need to win a stare-down to feel confident in my own abilities.