Sit up without moving your legs. Mark with chalk at your leg where you want the cape to fall. Make another mark a few inches lower. This is where you will cut. Use your measuring tape to mark this line all the way across the fabric. Cut across.
You can hem all around the edges of your cape if you are going for a refined look. For a rougher look, leave the edges raw. Over time, the edges will unravel. Alternately, you can blanket stitch to add a decorative look to the edges.
Cut out your hood and cape pieces. Save the scrap fabric to make the cape ties. Next, we will hem the hood.