You need 2 pieces of fabric, outer is 9 x 9"
Striped lining is 9 x 17 inches
Trim as shown
Iron some thin batting to the outer fabric for stability
Corners are 2 inch squares trimmed out of all sides
Sew the sides on all pieces, smaller one and larger stripe
Now fold cut outs to the seam which is in center and stitch in place to make a box shape
Sew around top leaving an opening to turn
Slip stitch this closed
Finish by folding down the excess fabric for a cuff.
Make sure the bottom is pushed in and is flat