I tried this out to make guest slippers. It took a bit of work through trial and error. The real problem is that thick felt like that is really expensive and the thinner stuff doesn't hold a shape as well
DIY T-shirt Felt Artwork. ◦a t-shirt % wool felt in a few pretty colors ◦small patterns of the shapes you want to cut out ◦a sharp scissor ◦pins ◦a sewing machine or needle and thread You can use wool felt or other materials.