If you're in a busy area like the Quicksand, don't be afraid to examine people (make sure your hands are warm first, they appreciate it) and look at their search messages. Most who are RPers will mention it, and a lot of those RPers will also add that they're open to walk-ups. Start with the obvious ones like that, since they're there in part to help you break the ice.
If they're not obviously open to walk-ups, sending someone a /tell before you engage never hurts either, even if it's just to make sure they're present at the controls.
If they're not obviously open to walk-ups, sending someone a /tell before you engage never hurts either, even if it's just to make sure they're present at the controls.