Spray the door with an all-purpose cleanser, coating it generously. Wipe it down with a lint-free cloth.
Fill a plastic bag with 40 screws and fasten the bag shut. Swing the bag against the door, creating nicks, dents and other signs of distressed wood. Continue this until you are satisfied.
Tape off any areas you want to remain untouched with painter's tape.
Dip a 3-inch foam brush in crackle medium and apply it, going against the grain of the door. Allow it 20 minutes to dry or as according to the package's instructions.
Dip a foam brush in the oil paint color of your choice and apply the paint with the grain of the door. As the paint dries, it crackles, creating a naturally distressed look.
Attach a piece of 100-grit sandpaper to the bottom of the electric sander. Run the sander along the sides and edges of the door to remove paint and expose the wood beneath the door. Continue until you've exposed as much wood as you like. Wipe down the door with a tack cloth when you are finished.