Set up your supplies in a well-ventilated area, and put on rubber gloves. If you're planning on working close to the paint, wear a face mask for protection.
Clean the surface of the piece of furniture or cabinets you're painting -- removing any existing oils or dirt -- using household cleaners. Sand down any gloss from the old paint, using 80-grit or 100-grit sandpaper, or a small finishing sander.
Cover up all surfaces not to be painted with blue painter's tape. Remove hardware like knobs, pulls and hinges.
Prime bare wood with alkyd wood primer.
Apply a coat of latex interior paint, tinted to a color that matches the wood stain you'd like your furniture or cabinets to imitate. For example, an oak finish would require the use of a light tan latex interior paint. Allow this base coat to dry thoroughly.
Apply another thin coat of the latex paint, using a lint-free cloth or small paintbrush. Paint one section at a time.
Practice using the graining tool on scrap pieces of wood, so you'll know how long of a grain to create on your surface. Press down on the tool, using your index finger, and move it at a steady speed -- rocking it back and forth to leave the grain stamp on the paint. Move to the next painted section, once you're satisfied with the grain imprint.
Allow the paint to dry for 18 to 24 hours.
Wipe or paint on another thin layer of latex paint. Use a dry brush or cloth to feather out any streaks. Allow drying time of two hours before adding the top coat.
Apply a coat of fast-drying oil varnish or polyurethane varnish to protect your faux wood stain.