Sweater Recycle - Tip in comment section: When knitters cut fabric they first stitch close to where they want to cut with a zigzag stitch to secure that the fabric doesn't unravel. This might make it less stressful when cutting into your sweaters.
Rice packs, use hot or cold. My mom has made these since I can remember and I swear I never have enough of them. The best for headaches and body pains.