I have made a lap quilt from wool sweaters I picked up in thrift stores and boiled/felted. I cut them into 3 or 4 inch squares and just made patchwork. The back is flannel and I used no batting and tied instead of quilting.
Wandajean- The idea I saw of wool mittens from sweaters was to trace around the childs hand....allowing for seam allowance. Lay the pattern at the bottom of the sweater so the ribbing will be at the wrist and cut the simple mitten pattern. Do the same for a lining. I suppose you would hand stitch the lining at the wrist turning under a seam allowance. These are not very good instructions...but I just saw the idea on pintrest without much instructions.