One way to show friendliness is to speak kindly to strangers. I don’t mean start random conversations with someone who could turn out to be an ax murder. I mean if someone is wearing an awesome hat, tell her. If you admire a person’s dress, let them know. “I love your hair!” Let people know their efforts have been noticed and appreciated.
This habit has been known to startle people, but then they smile and say, “Thanks!”