after years of it rarely being a problem, I had to set up a cancelation policy, I charged a base price that is the average of my income per hour
it seemed unfair to charge for a more expensive service cancelled vs a less expensive service and avoided tempting clients to lie, "no, that wasn't a new set, it was a manicure"
we didn't take credit cards at the time of appointment so, I lost the money if they never returned, but most, paid as the price of the next visit and even those who cancelled through no fault of their own (I said I wouldn't charge them) insisted on paying for the lost time
I didn't charge them if the time filled with someone on stand by or a new call
the issue is lost time/income, so, as long as the time filled no issue, it also inspired some to call a friend and offer them the time
a few would send someone in as a "gift" thinking they were paying anyway...
the problems came with the people who would lie
I didn't charge for illness or emergency, flat tire, sick child, worked with a hair dresser who charged a good client who turned around on the freeway, called me in tears, notified her father was dying.
amusing when some would lie about it and later talk about the last minute invitation... when they were supposed to be waiting at the dr's office or stranded on the 405 with a flat tire...
I worked in salons who would not discipline discourteous clients, I watched people who had a full day book sit and wait for clients who never showed up and had a attitude if we called to find out what happened to them. I've had more than a few "confrontations" (them angry, me quietly explaining how working for a living works and cheerfully offering to share the names of products I used successfully on them with their new manicurist who is independently wealthy)
usually a few visits to the walk-in quickie salons made them more appreciative
some find they liked the "walk in" aspect of quick and cheap