Although I don’t teach yoga, I believe what makes someone a good (or amazing) yoga instructor are the same principles that govern the rest of us. He or she needs to understand the concept of their teachings very well. The instructor needs to be a good communicator, be the example others would want to follow and be inspired by and have enough experience to be able to instruct in a safe way clients form all levels. Also keeping up with any continuing education and looking for ways to become better at what he/she does will make him/her better than others.
The instructor will also have to be dependable and reliable if he/she will keep the business growing.