I make it a habit to greet strangers when I walk past them. Old sales practice, but I find it really helps make my day light and often makes others smile.
Don't get me wrong, if I'm standing in a line somewhere I don't say hi to everyone. But I make it a habit to greet, or nod and smile, to every single person I pass by within say a few feet. Within reason of course, not in crowds, etc.
I'm a friendly guy.
