I must admit to being slightly antisocial. When someone asks me what that is, I give them the blank stare.
Now, I'm a fairly big dude. Not a giant by any stretch, but at 6'1" and 220 lbs, I'm larger than the majority. However, I have a charisma and presence that has made true giants blanch.
My blank stare is enough to make almost anyone just turn the other direction and forget they asked me a question. Those few who don't will usually follow up with ridicule or sarcasm. When that happens, I begin to glower. They then leave, even if they wanted to stay.
There are, however, a select few who are immune to that sort of presence. I can tell who they are, because they just give me my blank stare back. On the rare occasion that this happens, I break into a grin and explain that "this is a non carcinogenic way for me to get my nicotine fix, with a whole spectrum of yummy flavors". These folks have the constitution to look past the glower and tend to be smart enough to listen when I speak.
My method isn't for everyone, even if they have the presence to pull it off. I just hate people. Don't get me wrong, I love individuals, but people don't stop being people and start being individuals until you make them engage their brains, which almost no one does while put in public.