Whilst I usually think it is unhealthy to think of one girl as above the rest etc etc here is a roughish guide of how I calibrate my game.
After a while it becomes second nature and you can spot personality traits almost instantly that will help you tailor your style to them.
But yar this is a little off as a scale but meh its a useful basis
oh also for the other bit of the question yp I used to have 2 or 3 openers which were universal (not based on looks or the woman in any way) and would just shuffle through them throughout the night.
I would have one that you are sure works, one new one and one question you genuinely want the answer to.