Sometimes wool sweaters don't felt up quite the way I want them to. When they wind up being too stiff and boardy, I cut them into 6.5 inch squares and make small rugs out of them. These are approximately 2 x 3 feet in size and make a nice bath mat or a pet rug for a smaller dog or cat. I try to include the bound edge of the sweater as the edge of the rug, but these don't actually need any edging as the felted wool won't fray.
This pastel rug simply screams Easter and spring. The cream wool is from a blanket. I've learned that working with cable knit can be tricky, even after the wool has felted up densely, but I haven't learned so much that I can use it flawlessly yet. Still, I like the texture it gives this rug along with the Fair Isle knit and wavy lavender squares.
The embroidered corner pieces in this gray, black, and red rug are from a nice boiled wool jacket that I bought from a thrift store and wore ten years ago. I couldn't bear to part with it after it shrunk up too much in the wash, so I kept it all these years thinking I might do something with it at some point. And now I have.