“Is there anything else I should have asked you about that I didn’t?”
Asking this question gives the floor back to the person you’re talking with to see if there’s something obvious or hidden you may have missed. While some people won’t have anything to add, many times the most fruitful (or telling) information in an interview comes when letting the person being interviewed decide what question you’ve missed.
Try this innovative strategy in your next interviewing situation, and you’ll be pleasantly surprised! – Mike Brown