What to do next?

I am a terrible flirter, not only that but I find myself stuck in a situations like yesterday that drive me insane.  I was out with a friend of mine shopping.  We went into a store and had a lovely time trying on accessories.  As we were there, I struck up a lovely conversation and unintentionally flirted with the owner of the store and really felt like it was a mutual attraction.  So here is the question, and the challenge that I often have, how to move from there to the next level of actually exchaning phone numbers/taking it to the next level?  Maybe I missed a whole level of matturity/growing up.  I just don't seem to have picked up that skill.  It just sucks.  He was adorable, i know that there was a little bit of a spark I just wish that I could have capitalized on it more.  Another opportunity lost, unless I go back there again to look at accessories....