Rose, I suggest (with absolutely no expectations other than practicing for when you are really ready) the next time you're in the elevator situation, give the man an innocuous compliment ("I think that tie suits you") along with a related question ("How did you find it?"). Almost always they'll start talking and if they are interested in you in any way (and not just romantically) they'll engage in a nice elevator conversation with you.

Even though I have a girlfriend now, I still practice giving sincere compliments on the elevator, just to keep up my "small talk" muscles. Plus, if you get them talking, the pressure is off you somewhat.