A simple format: draw a cross with the vortex off center. Move the longest stick off center of the vortex. Cut the fabric on these lines. Then use all the leftovers from making the front, piecing them in a creative way. First sew the two verticle lines back together with the piecing in between. Then put piecing in the horizontal seam and sew it back together. Probably try to draw it on a piece of paper first so you can get the idea. Tried to make a drawing, but it won't load.