Take 3 pieces of 6" x 4" and 2 pieces 4" x 4" and length of the elastic must also be 4". Now fold both 4"x4" and 6"x4" bits in half and press with iron.
First lay the unfolded 4" x 4" piece and place the elastic and the ribbon, folded in half onto the back. Lay the folded fabric pieces as shown and make sure the folded edge is always to the middle.
Now place all the pieces as shown in the image and lift the corner of the first piece and tuck the last piece under then pin to hold everything in place.
Then stitch all the way round leaving a 1/2" seam allowance. Trim the corners as shown and the seam allowance.
Turn the pouch out through the gap in the middle. Use something pointy to poke the corners into shape.