you will probably have to look more for things to avoid than to do. Any technique that places stress on the wrist in support of body weight is not a good idea. There is a link to a question just like yours in the context of Pilates http://www.pilatesconnections.com/index.php?/topic/1537-carpal-tunnel-sy… which may give you further insights.
Carpal Tunnel Syndrome usually requires treatment. I have recently attended a workshop where the presenter Dr. Oestmann who is a physical therapist related personal experience with Carpal Tunnel Syndrome. He was able to cancel a surgery after trying treatment with a K laser. By his account, this condition was completely cleared up after three sessions with that laser.
Good luck for your client.