I actually like having meandering pointless conversations with somebody I'm getting to know. I think it really helps you learn a lot about the person, the things that pop into their head and essentially into the conversation can give you some pretty good insights.
Past that point, I just let the conversations happen if the other person is deep enough and/or has enough in common with you topics will eventually begin popping up...sometimes its asinine and fun other times deep and mind blowing. Besides forced conversation, at least in my experience, never really works that well and almost always falls apart, resulting in awkward silence. I find its best to just let it unfold and see where it takes you, much more natural and relieves you of the pressure of having to think of something to talk about.
One piece of advice I can give you (echoing the above) is ask questions. For example if she says "My brother is a pilot" don't think of something to say to top her or sound interesting, prod her for more information. "Really what does he fly?" or "that's interesting, how long has he had is license?". Doing so will help the flow of the conversation, allow more opportunities for new topics to pop up and c'mon chicks like a guy that listens.
