The best way to conduct interviews -- or any kind of research, for that matter -- is to check you ego and not try to make yourself look smart. Rather, asking a "good dumb question" is an approach that will often yield the best results.
This is the advice of the "CEO whisperer" Adam Bryant, who writes The Corner Office column for The New York Times. Bryant sees a good interviewer or researcher as essentially someone who is a good listener.
That's easier said than done, as is the case in life in general, Bryant says, many people are not really listening but waiting for their turn to speak.