Cable-Knit Ornament Turn an old sweater into a warm and festive ornament. Cut a 6-inch-long tube from a sweater sleeve. Slip a plastic-foam ball into the tube. Gather cut ends at the top and bottom of the ball using straight pins to hold the fabric in place, trimming where necessary. Glue red velvet ribbon around the ball as shown, dividing the ball into quarters. Use a red pearl-head pin to secure a felt poinsettia or a small purchased artificial flower to the top of the ornament.