How do you address the listener when you do not know his or her name or title? There are the 2nd person pronouns 너 and 당신, but those are generally either rude or awkward in most situations. I know that usually 2nd person subjects are just omitted, and this works fine it most situations, but occasionally, I really just want to say "you" to describe who I'm talking about. It generally works out fine with a simple hand gesture pointing to the listener, but I'm curious what would be done if, say, it was a telephone conversation and nonverbal communication wouldn't work, or other verbal alternatives in face-to-face conversations.
This used to really bother me when first learning Korean. Books teach a bunch of ways to say, "you" and then tell the learner, "but don't actually use any of them in an actual conversation." I haven't actually run into this problem recently, so I've apparently gotten used to it and/or coped with other techniques, but asking because I'm sure others have run into this same problem, and I'd still like to know more alternatives.
To be clear, I am looking for ways of address when you do not know the listener's name or title, so things like
name + 씨 or
title + 님 are not what I am looking for.