That's a good question. No magic bullets, but I think one principle is to keep it casual. A lot of journalists get so into the mindset of shaping a character in their heads that they forget to experience whatever it is they're doing.
E.g. When someone is walking through the buffet in a diner, that's probably not the time to ask, "How old are you? How long have you lived here?" Better to say "These yams look delicious" and see where the conversation leads.
E.g. When someone is walking through the buffet in a diner, that's probably not the time to ask, "How old are you? How long have you lived here?" Better to say "These yams look delicious" and see where the conversation leads.