There are some useful ideas on the Business, Marketing & Career Development forum [link=http://www.healthypages.net/forum/tt.asp?forumid=25]http://www.healthypages.net/forum/tt.asp?forumid=25[/link].
Here are some ideas I have seen on the forum, was thinking on these lines, it always good to others are thinking along the same lines. Freebies, bottled water etc. 6 for the price of 5. 10% with a advertisement/flyer (or maybe if client rebooks). 10/15% off if they recomend a new client.