How do you properly countersink a screw to ensure a flush finish?

To properly countersink a screw for a flush finish, first drill a pilot hole slightly smaller than the screw diameter. Then, use a countersink bit to create a wider hole at the surface for the screw head to sit flush. Adjust the depth of the countersink bit to match the screw head size. Finally, drive the screw into the countersunk hole until it sits flush with the surface.