Just one more suggestion.
One of my classes, the instructor taught a technique for piecing with very tiny pieces. There were so many in the class that most of us could not see the way she was laying them out.
my suggestion is, exaggerate the size your are demonstrating with, but show a finish that is the correct size.
Use a background that has a dark shade for it if you are using a lot of white or light fabrics. Light color if you are using bright fabrics and set up the room with the planning board on a plain wall the windows won't interfere with the seeing the actual work and getting pictures.
I'm a visual learner, if I can SEE it even when I'm working it, I can work it out properly so encourage them to bring camera to get shots of the work in progress, especially if they aren't doing them at the time.