Be sure to include a stamped, self-addressed envelope so the form is easy to mail back. Don't make your clients hunt around for your address or have to buy a stamp to give you feedback. Your investment in postage will be paid over and over again by the feedback you receive. The information you gain from this survey will be incredibly valuable in helping you develop and maintain lifetime clients. Also designate one person to receive the forms.
Clients feel more comfortable when they see an individual's name on the return address.
Other questions to ask. Depending on your business, you want to ask specific and directed questions to gauge the quality of your service. Again, keep the survey brief and to the point. The easier it is to fill out, the better the odds that clients will fill it out. Recently, I completed a simple transaction with a major bank.