My go to solution to this problem, back when I needed one, was as soon as the girl in question asked "what do you do?" I'd reply directly with "I'm a computer programmer - what do you do?" and should they say they are a musician or whatever I'd jovially reply instantly with "Oh well, I guess we have nothing in common then", and pretend that the conversation was over. They were always very interested to talk then, and the conversation was firmly on a flirtatious footing.

Writing this now, I realise that there is an corner case I hadn't covered in this plan. Solving it is left as an exercise to the reader, but I'd suggest something along the lines of "Emacs or vi?"