To slice a brisket properly, identify the thinner flat and thicker point. These two sections typically have grains running in different directions. Start by slicing the flat against the grain into thin slices, usually 1/4 inch thick. When you reach the point, rotate the brisket since the grain of the point often shifts. Slice the point against the grain as well. Cutting against the grain ensures tender bites as it shortens the muscle fibers.