I did use pick up lines when I was single.
I'd go up to a guy, and tell him that I came over to flirt with him, but that on the way over I lost my nerve. Then I would look helpless, and ask the guy to hit on me instead. Very effective.
Once, inspired by a friend's funny story, I pulled off the following. I used the above line to start a conversation with a guy who turned out to be a boring boor. So after making eye-contact with a guy behing him, I pointed to my left and exclaimed, "Holy shit! A diversion!" And when the poor dude looked away, I mouthed, "Help me?" I think dudes just love to rescue a humorous damsel in distress.