Do you stretch your clients?

When should they complete their flexibility exercises?

All of those questions are answered in the following resources:

Twelve dynamic flexibility exercises for racewalkers (they can be used for most of your clients)
http://members.aol.com/rayzwocker/worldclass/drills.htm

Huge free online book all about flexibility!
http://www.bath.ac.uk/~masrjb/Stretch/stretching_9.html

Some sample stretches using a stability ball:
http://www.apexfitness.net/html/exercise/articles/resist/dynamic_flex/