Use a mini roller to apply lightweight joint compound to the wall. Cover the entire surface, and make your last roll moving upward.
Look for peaks pointing upward after the last roll. Smooth down the peaks in a vertical fashion. Leave indentations in the plaster, using a drywall trowel.
Roll on additional texture if spots seem bare, and repeat the process for extra thickness. Allow the joint compound to dry for 24 hours.
Scoop a small amount of plaster onto your drywall trowel with a putty knife. Hold the trowel at a 45-degree angle, and skim the plaster onto the wall's surface.
Move the trowel in semicircular motions as you apply the plaster. Cover approximately 90 percent of the surface, lightly skipping over the wall and leaving some sections bare.
Sand lightly with a medium-grit sanding block once the plaster has dried to remove any loose plaster. Allow the plaster to dry for a day and then paint the wall.
Add water to lightweight joint compound so the mixture is about the thickness of pudding. Use a sea sponge and dab the plaster onto the wall to create texture. Remember, each person's sponged texture may look different.
Cover the entire surface using a random pouncing technique. Pouncing is basically the same as stippling. For additional texture, allow the first layer to dry, and then randomly add extra plaster to about 50 percent of the wall with the sea sponge.
Smooth the second layer of sponged-on texture with a drywall trowel to give a slightly layered look. The wall will look as if two layers of plaster are covering each other, similar to an aged wall.