Wash the wall with a mild detergent to remove any dirt.
Cover the floor where you are working with drop cloths.
Mix drywall compound and water together until it has the consistency of a milkshake.
Pour some of the drywall compound into a roller pan.
Apply the drywall compound to the heavy nap roller by rolling it in the pan. Using a heavy nap roller can help provide more texture to the wall than using an ordinary paint roller.
Begin applying the drywall compound to the wall in one corner with the heavy nap roller. Cover an area that measures approximately 3 square feet before moving on. Move the roller in the direction you want the texture to appear. If you want the texture to appear in a random pattern, move the roller in different directions. Allow the drywall compound to dry for the time specified on the packaging.