For the few times where I had to speak to someone about topics I don't care much about, I found that simply asking questions to learn about them ( as well as the person I'm speaking to) is enough.

"What team do you support? Has it always been the case? How do you think they compare to <well-known other good team>?" "What car do you drive? Any particular reason for that car model? What's the brand's best and worst things? Oh, that piece tends to break easily; pardon my ignorance, but what's the purpose of it?" "Any key difference in the way you hunt/fish this or that animal, or the time of the year during which you hunt/fish? I don't know that word, what does it mean? Do you have any anecdotes about some hunting/fishing you did?"

Those have to be adapted to the person and situation, but they are pretty good to keep a conversation going. People love to speak about their interests, and a lot love to even teach about them. Putting yourself as the listener makes them perceive you as nice, and you might even gather interesting information to yourself, or at least gather enough knowledge to have an easier time speaking about it next time.