Work with one small area at a time. Use the Sgraffito tool with the hollow side of the blade down to gently scratch fine, shallow lines along the sketched or traced design lines, then go over the lines a few more times, gradually deepening and widening the lines.
Evenly carve any wide design areas down to the depth of sgraffitoed lines. To avoid chipping the color, always pull the tool toward you and, in areas where two lines intersect, pull the tool away from a point on each side of the previously sgraffitoed line.
Use the brush end of the Sgraffito tool to remove any color particles and dust from the sgraffitoed lines as you work.
If the color becomes too dry, moisten the area to be sgraffitoed with a slightly dampened sponge, being careful not to overwet the piece.