I prefer no less than a full hour. That seems to work well for most students. Some of my students like two hour sessions. With a good teacher, yes, it will be intense, but you’ll be having fun, so the time will just fly by. That said, if you truly find 60 minutes is too long for you, then sure, cut it down to 45 or 30. Personally, I don’t want to spend 15 minutes studying my calendar to find a good time, booking the lesson, and setting a reminder, all for a 30 minute lesson.

I prefer 45 minutes. I find 30 minutes too short and one hour tires me.