Roll out the base coat on the wall using a standard paint roller and extension pole, if needed. Allow the wall to dry overnight before attempting the glazing process.
Roll or brush on a layer of glaze in an area that you can work with before it dries. Do not paint the entire wall with glaze, as you need to work with it while it's wet.
Dab the wet glaze carefully with a wadded-up rag. As you dab the wall in a random fashion, adjust the shape of the rag and the amount of pressure you're applying to the wall. This keeps the glaze from taking a wallpaper-like pattern and produces a unique pattern on the wall. The glaze will dry and appear to have more depth than you would get from a single-color wall.
Roll out another section with opal glaze. Continue to blot the glaze from the wall using a wadded rag, adjusting the random pattern and pressure until the entire wall is complete. Try to finish the entire wall in one session so that your style remains uniform. Allow the wall to dry overnight before applying additional paint.
Add additional coats of glaze. If you wish to enhance the depth effect even more, you can add additional layers of glaze to small sections using a paint brush. This will create accents of more depth and shadow in the paint, without having to reroll the entire wall.
Clean your brushes, rollers and other equipment using soap and water. Make sure that you remove all of the paint before leaving the equipment to dry, or else it will become stiff and useless.