I was a martial arts instructor during the summer before I went to college, and probably would still be if I’d gone to school in the area where I lived. I took my third degree test during my senior year of high school, and was a volunteer working with the younger students before they hired me. So, yeah, that’s where the advice comes from and a lifetime spent around martial artists.
At third degree, my rank is Sabumnim in the West Coast organization. These days though most teaching happens through this blog. The insider understanding of the legal/business side helps a lot.