Paint the wall you want to sponge in the base color you want to use in the design. Don't paint the base coat with any paint with more gloss than a satin finish. Let the base dry completely before moving on.
Mix two parts of the glazing liquid together with each part of the second paint color for your sponge mixture. The darker you want the paint to appear, the more you should shift the ratio in favor of more paint and less glaze.
Moisten the sponge lightly in some water. Paint the glaze mixture onto the sponge with a brush, and wipe off any excess with a cloth so that the sponge is just lightly coated.
Press the sponge against the wall and then twist it. Continue to press the sponge against the wall while you use a variety of different motions to create different patterns of mottling. Recoat the sponge when the paint starts to lighten on the wall, and continue until the entire wall is covered.