For 4 years, my job at my university was making small talk with new students and their parents. Literally just going up to strangers and trying to make them feel comfortable, warm up to the idea of talking so they would ask questions. And at lunch time, I had to gather up students and eat lunch with them. So it would be me, and maybe 5 or 6 shy freshmen or would barely talk. That was my lunch time everyday in the summer during college.
Honestly, it just became an internal thing for me. It wasn't so much about how talkative the other person is, but how you bridge that comfort gap. I stopped being so guarded about myself and usually people follow suit with that. I literally just think of that person as a friend already, and start talking to them. Everybody is going to be different, not everyone wants to talk about themselves even if they do like you or feel comfortable. My goal was just to get them to place where they knew that they could ask anything and it would be cool.
I also like listening to people talk about themselves, which helps. So if someone tells me they're from some town I've never heard of in New York or Kansas, I have this earnest interest in knowing more about it.