You could make them like I did.
It was damn easy to do. Buy a pair of sandles that fit you (a pair that wraps around the front of your foot and around the ankle), and a dark blue turtleneck. Cut the arms off the turtle neck and open the seam. Cut each arm in half (like at the elbow), fold over the part where you cut (so you're using the part that normally goes from shoulder to elbow) and use a hot glue gun to connect that to the toe side of the sandel. Then fold the sides up a couple times and hot glue that along the sides of the sandel. Glue the part that wraps around your ankle to the fabric, fold up the back of the ankle and glue that closed. Check my photos and see what it looked like. If you wan the bulgy part to look like it did on mine you just fold the cuff over twice.