Here’s some great consulting advice from Peter Drucker:
My greatest strength as a consultant is to be ignorant and ask a few questions.
As a consultant, it’s tempting to take on the role of expert. After all, a consultant is an expert. But don’t let that get in the way of learning more about your client. In fact, when working with a client, expect to ask more questions than give answers. You’ll learn more and the client will be more confident about your abilities, since you’ve taken such a strong interest in exploring their needs and problems.
"Ask questions" from Become a Consultant at ConsultantJournal.com.