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.
★ Les Tissus Colbert: Kelly's Corner: tutorial on making crocheted baskets. Blog in German but Google Translate helps--i think an intermediately skilled crocheter could suss out how to do this.