Place the drop cloth on the ground. Lay the plywood onto the drop cloth. Apply two coats of primer with the paint roller. Let each coat dry completely before applying the next coat.
Draw parallel pencil lines at three inch intervals across the primed plywood, using the L-square and the straight edge. Remember, precision counts when it comes to making sure the lines are parallel.
Pour the burnt siena paint into all three plastic bowls. Add enough black to the second bowl to darken the color. Add enough white to the third bowl to lighten it. The rule is: easy does it. You only want to change the color enough to add variety.
Daub one of the sponges into the unmixed color, making sure its entire front is covered with paint. If the sponge is dripping paint, scrape off the excess. Using the pencil lines as a guide, gently stamp a brick pattern onto the plywood. Leave about one-half inch between each brick.
Daub the second sponge into the darkened color. This time, however, make sure that the paint does not cover the sponge evenly. You can do this by squeezing and folding it. When you have loaded the sponge with paint, stamp its pattern over one of faux bricks. Repeat this process for each individual brick, so that each brick has its own, unique character.
Daub the third sponge into the lightened color. Again, ensure that it is not covered evenly with paint. Do not use this sponge on every brick. Only use on a few isolated bricks to create highlighted areas.