How to start conversations with random girls?

I'm a 19 year old male college student and I was wondering if you guys could give me some tips on how to start conversations with random girls I would ordinarily have no business talking to, for example someone sitting at a coffee shop or walking out of class.

I'm not a very awkward person, I just have no idea how to go about this quite honestly. It's much easier for me to meet people through sports or clubs or something but I'm pretty busy and my current commitments make it really hard to meet people through those kinds of things.

Thanks!