Sand your concrete floors with the sander. This will remove any loose sand or dirt and prepare the floors to accept the primer.
Wash the floor with soap and water to remove any dust from sanding. Allow the floor to dry completely.
Apply the primer to the concrete floor. Allow the primer to dry completely. The primer will seal the concrete and smooth out the texture.
Paint the concrete floor with the light brown paint with either a roller or a brush. Let the paint dry.
Apply the medium brown paint to a small section of the floor. Make sure all your brush strokes are in the same direction. Take the graining tool, and with a back-and-forth motion, drag it through the paint. This will create the look of grain on the floor. Repeat the process until the entire floor is covered.
Create a darker grain by dripping the dark brown paint in random sections of the floor, and use the graining comb to create darker wood lines.
Dip a cotton ball in the dark brown paint to create knots in the wood.
One the floor is completely dry, apply a sealant with a roller brush. For a more realistic wood look, use a dull sealant. For a glossier finish, use a high-shine sealant.