I explain my cancellation policy at the first visit. I require 48 hours for a cancellation. In the event of sudden illness, I make an exception, but I don’t tell clients that until it occurs. I also let the first short notice slide if the client offers to pay for the session. There is some nuance to how I handle cancellations. And for my long term clients, I am more patient. Someone misses one out of ten scheduled times is different than missing four out of ten sessions. I do have a client that misses sessions fairly regularly due to their work. We came to an agreement where they pay half for cancellations less than 48 hours out.
The great clients always offer to pay for their missed sessions. If they are frequent cancellation type of clients, we talk about it and find some solution. I have one other client that pays a little extra to schedule last minute and at odd hours. They call and I fit them in when it is possible. This client often flies back into town and needs to work out the kinks of a long flight and tough business trip.
Basically, I try to work with my clients as professionally as possible. The ones that don’t understand that my time is as valuable as theirs, pay for missed sessions or move on.