Heat a cast-iron griddle or large skillet over moderately high heat. Work with one piece of dough at a time: On a lightly floured work surface, dust a ball of dough with flour and roll it out to a 9-inch round, about 1/8 inch thick. Griddle the tortilla, turning once, until browned in spots and pliable, about 30 seconds per side. Wrap the tortilla in a towel and repeat with the remaining balls of dough.