Start from an Image
As yoga teachers, many of us are more visual and kinesthetic than anything else. If this is true for you, consider starting your writing from a photograph.
There are two ways you might want to do this. One way is to do a Google search for images of a yoga class. Pick one that you like. Then, using this image, write down all the things it calls to mind that you might want to include in your teacher training manual (or other writing). For example, if it’s a photo of a teacher doing what you consider to be an unsafe adjustment on a student, the topics of “hands-on adjustment” or “working with students with injuries” might be ones that come to mind. Or even something as simple as “what to wear to yoga.”
The other option, which I think might bring more of your own unique perspective to your writing but also involves more logistical planning, is to have someone come in to take pictures of you and the people in your class as you teach. Remember to get everyone’s permission if you do this (and if you want to have the option to use the photos in your marketing materials, be sure to have signed model releases or to have their signature on the sign-in sheet serve as such). Then do the same thing. Go through the images and see what stands out for you and what it calls to mind. Write this down. Maybe you see yourself talking and you write down “voice, projecting, communication.”
Whichever technique you choose, once you have your list of topics you can jump into the Top 5 Ways to Get Started.