Something I picked up while living in Britain and have kept since: quality over quantity.
So my classes are capped at eight. People ask why I do not take more. Take more and I cannot follow each person closely, and without that the learning does not land. There is no point taking your money and your time for that.
The intake conversation
Before anyone joins a class there is a forty-five minute conversation. Not to close a sale, but to work out whether this class is genuinely right for you.
I have advised people to go in a different direction entirely, even when they were ready to pay. Taking someone I can see is a poor fit does them no favours.
Three things I believe
One. Teaching English is not a competition over who enrols the most students. It is about whether you can actually speak and use the language.
Two. Small classes exist so people speak. With eight, everyone gets their turn. Thirty people sitting quietly while the teacher talks go home with exactly the same stiff mouth they arrived with.
Three. I would rather take fewer people and stay with them for the long run than take many who attend a few sessions, feel it is going nowhere, and leave.