Some day I'll have some paying students, but for the last 11 years mine have all be no-charge students. I've taught mostly in parks or was hosted by Military Gyms and was allowed to charge if I wanted, but I wasn't paying anything so I wouldn't charge anything. Now I'm paying rent for my school, but since I can afford to pay it out of my own pocket, I'll continue to teach for free until I can't afford it.
All of my students are the Dojo Janitors. We each grab a broom beginning and after class and sweep the floor and clean the smudges from the windows and mirrors as needed. I didn't take classes for many many years, when I wanted to, because my parents couldn't afford to send me to one. I wish I had thought to ask the instructor to be the Janitor in exchange for lessons, but at the same time I'm glad that I didn't. There are so many things that I've internalized and have a better understanding of because in training by myself I've made the discoveries instead of having them taught to me.