Mix flour, soda and tartar in small bowl; set aside. In large mixing bowl, blend sugar and butter (due to consistency of dough, use dough beaters). Add egg and vanilla; blend thoroughly. Blend in dry ingredients. (Note: If desired, divide dough in half, thirds or fourths and blend food coloring into each part.) Wrap dough in wax paper, and refrigerate at least an hour. Roll out dough and cut out with desired cookie cutters. Bake at 375 degrees for eight minutes. Let cool on racks. Decorate cookies with frosting and/or seasonal colored sugar or sprinkles.