Nothing. Let the sheer awkward silence overcome her while you simply stand there and be comfortable in it. Nick Sparks has covered this a couple of times in his lectures too. If any of you haven't seen them, I highly recommend checking them out (How to Hold Conversation like a Man). It's painful at first, like any other thing is in seduction, but it's important in becoming comfortable.

Let me try putting it another way. Think about when you're out with a girl and you're dominating the conversation (while still listening to her stories), but then suddenly you run out of anything of interest to say. You have the brief moment of panic and immediately come up with the very first topic that comes into your head. And no matter how great you are at bullshitting interviews using this strategy, your topics become quickly stale and - well, rinse and repeat.

Here's something you may not have considered: she's freaking out just as hard to come up with something to say. Even if she isn't interested in you, she's doing it. Past experiences of millions of human interactions have simply ingrained into our heads that Silence = Bad.

But I'm here to say it's not bad, in fact it's good. Taking a few seconds to relax and mentally compose yourself will allow her time to come up with something to say while taking the pressure off of you. As a bonus, you'll appear all the more confident (and therefore act more confident) because silence doesn't affect you, you've CLEARLY had millions of interactions that include long silences. On top of that, now she feels the need to qualify herself to you by thinking of something interesting to share.