I am an orchestra teacher and ironically, a lot of what we learn and what helps kids learn is visual. Having a collection of images with strategies that work for other teachers is invaluable.
Here is one:
https://www.pinterest.com/orchestrateach/I chose this one because it is another elementary orchestra teacher that has spent time collecting relevant resources relating to teaching orchestra to beginners
Here is another:
https://www.pinterest.com/banddirectorsta/It's not orchestra, but the organization puts out a lot of useful content about organizing your teaching, running your program, and teaching kids learning strategies.
Celia Garner-Prouty