Customer Questionnaires - A series of questions answered by the customer about the business. When customers come to your shop or location to review your product. You could give them a questionaire to fill inn. The questionaire will help you develop or to see what product people most like and whats new out there.

Customer Comment Cards - Instead of asking people questions, you can make them feel in a comment card to help them to be more honest in revealling what needs developing and what they are doing good at.
A comment card can be writen by anyone who come in the business.