Anything. You can get away with pretty much anything. So I guess it all comes down to what YOU want out of the interaction with her. Since there are some topics that are more effective to achieve something....but will be useless or even damaging to achieve something else.
Most of the time I use a topic that is somewhat related to my opener. If you can't do that then it means your using the wrong openers known as pickup lines:
hey, do you have a map? Because I keep getting lost in your eyes
if I could rearrange the alphabet, I would put you and I together
did you just make a u-turn? Because u turn me on.
Avoid pickup lines like the plague because they will not help you. Even if she reacts positively.
I think there's an article about openers. Search for it. otherwise, don't stress too much.