1. Wearing safety goggles and rubber gloves, remove dirt or loose concrete using a wire brush or masonry chisel and hammer, then power-wash the entire slab with a pressure washer or a garden hose fitted with a high-pressure nozzle.
2. Following manufacturer's directions, wash the patio with a concrete etcher to rough the surface so the stain adheres. Rinse thoroughly and let the concrete dry for 72 hours.
3. Have a clerk at the paint store add and mechanically mix slip-resistant additive into the base color of concrete stain. Use a long-handle roller to apply the base coat (grout color) of stain (this patio uses light taupe), in small areas at a time and work stain into the concrete surface from two directions. Base-coat the entire slab. Let it dry for at least 24 hours.
4. Measure and tape off a 6-inch-wide course of "blocks" along the outer edge of the slab. Then measure off 8-inch intervals and apply tape the length of the slab. Tape off the individual rows of "blocks" according to your desired pattern.
5. Using the same technique as for the base coat, roll the block-color stain (the pattern shown uses medium gray) over the slab. Let dry for 24 hours, then remove tape.
6. Use a small paintbrush or rag to lightly dab water-thinned stain on the bricks. Use contrasting darker (black or dark brown) and lighter (ivory or buff) colored stains for a textured effect and to soften the crisp grout lines.