Measure the length of crown molding you will cut, using a tape measure. Mark the back side of the molding with an "I" or "O" with a pencil to indicate which end is for the inside or outside corner.
Place the crown molding on the compound miter saw table. Line up the cut line with the spot you marked for cutting.
Change the angle of the compound miter saw blade. Release the locking mechanism and move the blade to the right or left, depending on the angle marked on the crown molding.
Turn on the saw. Pull down on the handle slowly and cut the crown molding.
Turn off the saw and remove the piece of wood. Dry-fit the crown molding together to ensure the cuts are correct. Continue making cuts for the crown molding project.