After some time in working with a client, provide them with a survey to get a feeling for how you're doing. This can be delivered back to you electronically or by mail. Keep it short. Five or six carefully crafted questions can offer valuable feedback on ways to improve your business practices. At the end of the survey, reaffirm that all their information is private and confidential. They need to know you won't break their trust.

Variation: Make sure and state they also have the option of giving their name and providing permission to use their words in your marketing efforts. In doing so, you may find yourself with some nice materials for testimonials.