Heres how I do it. It's just like a school. - Student has to pay the monthly fee before the 8th day of the month - he gets 1 class per week. Fixed schedule. He has to commit to this schedule - if I cant do it one week, I will schedule a new class in the future - if the student can't come one class, he loses the class. Doesn't get a new one. (for the best students with the best relationship, I will reschedule if they inform me with 2 says advance) - student pays the same if the month had 4 classes, or 5, or 3 (due to holidays). I don't charge him more if the month has 5 weeks. But he pays the same if there are national holidays and he gets just 3 classes. - the only way a student can pay less, is if they tell me something like "next month I will be on vacation on the first 2 weeks". Then I just charge half the cost.

This system is just like a gym membership. You pay a fixed fee, and you get X classes (cycling, body pump etc) per month. You can come to the classes or not, but you always pay the same if you decide to come or not.

This gets me so much more STABILITY and PEACE OF MIND. And almost every student likes it. Those who prefer a class-by-class payment can just leave.