My new FAVORITE fibers material to teach is WOOL FELTING! I love it... my students love it!
I bought all the supplies from Back to Back Alpaca. They sell classroom sets of foam, needles, wool "canvases" and roving. Plus... they offer a teacher discount! It is very affordable once you get set up, the roving goes a LONG WAY!
The biggest teaching tip... teach PROPER NEEDLE FORM! Straight up and down, not too fast, not too hard. I have about 6 needles break over the whole unit, so having an extra dozen is required... just in case! But once you correct a few, they get the idea and are more careful.
We started with the wool yarn first, breaking up the space with simple lines and shapes, then filled in with the roving. I recommend staying abstract your first year teaching, then going more realistic if you choose to. I had a few students make their's more realistic, which was fine with me. As the teacher, I have been learning how to teach this material... having my own learning curve to overcome first. Next year I will be more creative with my inspiration. I needed to see how they handled this material a couple times first. It has been much easier than expected! I can't wait for next year!