Form a slab just as you did in Steps One and Three. Trim one edge into a straight line using your potter's needle. Laying it so it abuts one edge of your base, mark and trim away the clay so that the new slab will fit snugly in between the interior surfaces of the two sides already in place. Trim what will be the upper edge to the height that you will want the finished pot to be.
Create a second slab and trim in the same way.
