Providing good customer service is often a matter of common sense, but that doesn't mean it comes naturally to all business owners. For some, in fact, it means behaving differently than they do in other business situations, says Richard Proffer, a counselor at a University of Missouri Small Business & Technology Development Center. If you are used to fighting about every detail of a business deal, say, you may have to adjust your attitude. Ditto if you feel that selling is a zero-sum game; to win customers, you will sometimes have to make them feel they have won, too. The pages that follow are a guide to providing excellent customer service.