I'm not sure I was always a great interviewer, but thanks to the tutelage of some tough editors early in my magazine-writing career, I became one.
I was pretty good at asking the "next" question mostly after years of hearing my dad go on about lazy reporters on the TV news who took answers that begged follow-up. These are the "hows" and "whys" that you wish you knew but the reporter didn't ask (or the editor cut out).
My problem was that I was often unsure of what to ask because I was afraid of looking stupid. My editors assured me that I wasn't dumb, and if I honestly didn't know something, I'd become a better reporter by learning it. So I put my fears aside and sallied forth. Never, the ensuing decades, has anyone ever told me I've asked a stupid question. Lesson learned.
I also keep the readers in mind. This is especially helpful when we're covering a subject we know well. There's lots of context and background information we may have that our readers don't. And that makes it easy to leave out of the finished piece. But remembering to ask sources about this kind of thing gives us more material to draw on to tell the story in a way that works for our potentially less informed readers.
This means I spend a lot of time developing questions. Sometimes I even ask others what they would like to know about the topic and include those questions as well. It may seem like wasted time, but better questions yield better answers. So the time I invest ahead of the interview is rewarded with more source material.
Take a few minutes today to think about the questions you ask when you're gathering information for any project -- a writing assignment or something else. Are you asking the right questions? The best questions? What questions are you asked that you hate -- and how could you rework them to make them better for you and the asker?
Read my post on interviewing filmmaker Albert Hughes (Book of Eli), complete with some tips for better inquiry.