Use a bristle brush to clean off any loose particles from the wall.
Remove the strip of tape from the drywall tape, and apply the tape over the crack in the plaster.
Use a spackle knife and apply a layer of joint compound over the drywall tape. Allow the mixture to dry, and then apply a second coat.
Sand the surface with sandpaper to create a smooth, even finish. Be gentle and move your hand in a circular motion.
Repaint the walls. Joint compound results in a white finish. Apply paint to match your existing wall color and hide any evidence of a repair.