Apart from the first cash-in-hand lesson, I don’t accept anything less than 2 or 4 lessons paid for in advance, which covers a full month of weekly/fortnightly lessons. This shows commitment for at least a month of rent!!
Still doesn’t eliminate the risk of people cancelling all lessons forever, 48 hours’ before their next scheduled lesson, which they have a right to do. I don’t mind this though, as this still gives me enough time to rebook the slot (hence 48 hour rule) and then for the regular slot renewal, I just take someone off the waiting list, which can be quite quick too.
Ts&Cs are covered upon booking either face to face or by email. They are included in more detail on my invoice which they get after their first lesson, ready to start paying advance blocks of lessons.
I like the idea of 2 weeks notice for stopping lessons – I might try this. But to be honest, having monthly lessons paid for upfront sort of eliminates this anyway, as like you say, people know the system is monthly, so can tell me ahead of time.
This also brings me to the issue I keep hearing about – first lesson cancellations. What Matthew calls “bad debt”!
One solution might be to keep a “non teaching hours” slot free each week for people to piss you about in, so that you care a bit less.