I get a lot of excitement from meeting someone new, so I only really do second punts as an exception. My rule of thumb is that if at the end of the first punt I find myself thinking 'I will definitely see her again', chances are that the second punt will feel better.
However, if I am only thinking 'I would see her again' (or worse), the likelihood is that the second punt will, at best, only be as good as the first (and probably won't be).