Make your paint washes by mixing equal parts paint with water in the containers. Protect the floor where you will be working with plastic sheeting; mix your paints on the sheeting. Usually about three different shades of reddish-brown paint ranging from a medium to a dark hue will suffice.
Paint the washes onto the bricks using brushes. Avoid painting the grout line as you progress and remember to vary the different colors throughout. After it has dried, you can apply another coat if needed. You can also touch up or completely paint the grout line with your gray wash.
Add a sparse layer of an alternate paint shade in order to enhance the color depth and texture of the brick. Lightly dab your brush into the lighter brick paint shade and dab it onto the darker shaded bricks, and vice versa. Use small amounts of the gray wash on some of the bricks to lighten them if desired.
Protect and seal your completed brick wall with a polyurethane sealant. You can use a high or low luster finish depending on the amount of shine you would like the brick to have. Brush on the sealant, making sure to work it into the bumps and cracks. Open as many windows as possible to allow for ventilation and leave the area to let the polyurethane dry.