Ask ten volunteers to complete the survey and note anything that is unclear, inappropriate or difficult to answer. Interview the test group to identify any other potential problems with the questionnaire. Review the pilot data you receive to see if it really answers your questions and provides a direction for necessary action. Time your survey carefully. Avoid holidays and the summer in order to maximize response rates.
Time is money.
Respect your clients' time. It should be possible to complete the questionnaire in 15 minutes or less. Otherwise, it's unlikely you'll get many responses. Providing a stamped, pre-addressed envelope increases the return rate. Include a brief covering letter stating that you value your client's opinions and you want to ensure you are meeting their needs.