1) First step is to adhere the plywood board to the wheel (if you use commercially available wheelboards, skip this step). Center a small amount of clay on the wheel and spread it as if you were throwing a plate. It should have a valley in the middle for the board to stay adhered. Make 3-4 circles with your finger and press a cross into it, like this:
2) Now slightly wet the surface of a wooden board and place it on top. Lightly tap the center and level it (run your wet fingernail along the outer edge, if it is too high on one side it will show up, and then you tap it into place).
3) Measure/ estimate the amount of clay you need for the body of the shibo, and center it. Compress the bottom and pull up the sides in a cylindrical shape. You can put in the gallery now or later, as you prefer. Thin out the walls as much as possible, because the upper half of the shibo should not be trimmed.
5) Once you have your desired shape, form the spout. Reverse your hand as in the picture and use your other hand to push down the clay in sweeping movements to get the most symmetrically formed spout.
Rather than undercut the piece with wire, just remove the excess clay from the bottom and cut 1-2 cm into the bottom - level with the board - with a sharp knife (I use a purpose-cut sawblade), to allow some air to flow in between the board and the clay. This eliminates the risk of warping while drying. Once almost leather hard, you can cut it off with your wire and dry it upside down for a while before trimming.
6) With the caliper, measure the width of the lid opening.