I really like author Paul R. Timm's advice to stop asking your customers the "typical" questions and instead ask them open-ended questions.
Here's what Timm recommends:
- How was everything?
- Can I get you something else?
- Did you find everything you need?
- Will that be all?
- Was everything satisfactory?
- What else can I do for you?
- What else can I get for you?
- What else can I help you with?
- What else could we do to better serve you?
- How else can we be of help?