Choose your primer, paint finish and paint color. Exterior gloss, semigloss, satin and matte can be used effectively for an exterior door. All exterior paints are weatherproof and washable. Your paint supply store will have a sample of each available for you to choose from. Keep your home's trim and exterior wall color in mind when choosing the color that you want and have it mixed. Select a compatible primer too.
Locate a level area, set up two saw horses, remove your door and place it on the saw horses.
Remove all of the door hardware. Cover any surfaces you will not paint, like glass, with painter's tape.
Clean any dust and dirt off of the door with a mild detergent and water. Allow the door to dry.
Sand the door's painted surfaces with your palm sander. Sand any trim by hand. The finish should be dull so it will easily absorb the primer and paint. Rinse off the door and allow it to dry.
Paint on your weatherproof primer and allow it to dry.
Paint your exterior door with the paint that you selected. Allow it to dry, remove the tape and reinstall the hardware.
Rehang and level the door.