Sand down your wood furniture using the 50- to 80-grit sandpaper in a circular motion. This will remove any paint, varnish or finish from the wood.
Roughen up the wood by using the screwdriver to create deep marks and scratches on the wood surface. Keep to the direction of wood grain when creating longer crevasses with your screwdriver. The rougher your surface, the better. Dints, imperfections, and deep scratches are characteristic of barnwood.
Apply clear bonding primer to the entire surface of the furniture using a large paintbrush. Make sure you are working in a well-ventilated area. The bonding primer will adhere to the exact shape of the wood, including all of the scratches and dints, while keeping the wood protected from swelling and water damage. Clear is the ideal color choice for barnwood primer as it allows the natural color of the wood to be exposed. Let the primer dry overnight.
Apply your desired paint color to the wood surface using a dry brush painting technique in quick, wispy brush strokes. Make sure to leave wood exposed in some areas. Let the paint dry for four to five hours. Soft, neutral colors such as antique white, mustard yellow and teal gray fit the barnwood style.
Scratch up the painted surface using a wool wire pad. At first, use small circular motions, then use the wool wire pad to create elongated scratches in the direction of the wood grain. You may want to use the screwdriver to create a few more dints in the paint as well.
Paint two thin coats of clear polyurethane on the surface with a large paintbrush. Wait overnight before applying the second coat.