Having something in common
The other advantage of waiting until you’re in a social setting like this is that it gives some indication of what each of you likes to do in your downtime, and shows that you already have at least something in common, which is a great start.
It also makes talking to someone so much easier. Instead of knowing only two things about a woman – that she’s in front of you and you think she’s hot – you now know at least three – she’s in front of you, you think she’s hot, and she’s really into Iron Maiden (or whatever you both happen to be doing at the time).
Your odds of being able to open with something that doesn’t sound lame have just increased by about 50000%.