When I first started, I did do offers. However, my prices are reasonable anyway and my offers were literally only attracting clients that were after cheap deals, so they did not stay as loyal clients.
I have lots of amazing loyal clients, all of which I have gained through word of mouth and came to me without any offers at all!
I do introductory offers though if I am offering a new treatment, normally for a month.
I also have a couple of packages which are all year round and printed in my treatment menu. Each includes two/three treatments and works around £5/£10 cheaper than having each treatment individually.
Completely agree with CFBS, constant offers on your treatments devalues your service and unfortunately does attract the wrong clients.