Cut mouthpiece to desired length using tool #11.

With the same knife, shave off strips of clay lengthwise on the mouthpiece to taper it.

Clean inside the entrance of the mouthpiece with tool #2 (curved end).

Use the edge of the knife to scrape the mouthpiece to a rounder contour, eliminating some of the angles.

On the tip of the mouthpiece, round off the sharp edges. Smooth mouthpiece with wet fingers and a damp paper towel.