A cancellation an hour before is money unless this runs immediately.
Find every client who asked for that day or was told we were full.
Message them the open time, first to reply gets it.
When someone takes it, create the appointment and tell the others it is gone.
Note the cancellation on the original client.
These are instructions for the assistant, carried out one at a time against your real records. Each one still goes through the same checks as if you had asked for it yourself.
Once you have an account, ask for "Fill a cancelled slot" and it is added as your own recipe. From then on it runs on your records, not on an example.
From the first message to the chair.
Run it the same day. A no-show contacted that day usually rebooks.
The single highest-value habit in the business.
Two days after a first appointment, which is when they decide if you are their place.
Monthly. Everyone who has not been in for twice their usual interval.
For anything sold as a block of sessions.