Not a great lead itself, but a useful poke a hippy at a festival taught me when the opening conversation starts to fizzle out a bit: "what do you want to tell me? It can be anything at all, take a moment to think about it." Then sit with the silence a bit (don't stare at them, let them think).

Some people will tell you some wild shit and/or open up like crazy if given this invitation. The person who used it on me got my whole life story, shit I was trying to work through by (in part) being there in the first place, etc. The last person who I did this with told me some defining moments in the development of their politics and worldview.

Create comfort, give an open invitation and a little space, and you'd be surprised how quickly you might move from small talk to more substantial stuff. Recommend everyone try it once just to see what the outcome is, so far it's been pretty neat.