Roll dough out on a lightly floured surface to a thickness of 1/8 inch. Cut out cookies, using a 2 1/2-inch round serrated or other decorative cookie cutter. Arrange on prepared baking sheets. (Reroll and cut scraps.) Bake the shortbread, 1 sheet at a time, until golden and firm, 8 to 12 minutes. Transfer to a wire rack to cool.