Sand the shelf to scuff a glossy finish. Wipe off the shelf with a damp rag.
Apply a layer of latex paint for a base coat. Don't worry about achieving full coverage, as you will paint over this coat. This color will show only in spots where the top coat of paint is distressed.
Allow the base coat to dry. Rub beeswax on the shelf with a rag. Apply the wax to places where you will want the base coat to show through.
Paint the finish coat of paint in the color of your choice. Use a wide paintbrush. Apply even strokes, in the same direction as the wood grain. Let the paint dry.
Rub the waxed areas with a rag to remove the top layer of paint. The paint will come off the waxed areas with ease. Lightly sand the shelf. Focus on removing paint from the edges of the shelf and other areas that would become naturally worn. Keep sanding the shelf until it shows the desired degree of wear and tear.