Measure the air vent cover using the tape measure. Choose a decorative air vent cover of the same size that matches your decor. If your home is modern and simple choose a plain cover; if your home is more decorative choose one that has more lattice-work.
Spray paint the original air vent cover in a well-ventilated area. Choose a paint color that matches the paint, wall paper or fabric wall covering in the room in which you are wishing to hide the air return vent. Allow to dry. Spray an additional coat if needed and allow to dry completely.
Remove the existing air return vent cover using a screwdriver. Place the new air return vent cover onto the air return vent with the screwdriver.
Place a piece of furniture slightly in front of the vent to hide it even more, if the vent is located in a place where this is possible. Do not completely block it, however, to prevent problems within the heating and cooling system of your home.