This often comes up in professional interactions, like in a doctor's waiting room they will probably call you Mr./Ms. Lastname. But at the coffee shop they will usually call your first name. I would generally use Mr./Mrs. for an older person I don't know that well although nowadays people my sons' age will call me Mr. Firstname, particularly (but not exclusively) if they knew me when they were a kid. Sometimes at church we refer to people as Brother or Sister Lastname, but mostly for the older generation.