So I went to work making a pattern (really hard - I traced the shape onto the fabric.) Then I cut out 4 of the green material and 2 pieces of the Insul-Bright Lining fabric. (Shown here is one side only - you need to make two sets.)
Then iron and sew the 3 layers together with the outside of your fabric on the outside. . . does that make sense?? Here is a picture. . .
Sew a couple of stitches up the center to secure the insulation and make it look decorative.
Then repeat for the other side.