Repair and cracks or damaged areas on the door. Take a damp towel and wipe off any dirt or debris from the door. Smooth the surface to be stenciled as evenly as possible.
Paint the entire door with a latex or oil based paint. A flat paint works best for stenciling. Choose the letter stencils. Pick the font and size of letters to use for the door.
Pick an area of the door to stencil. Use a level and pencil that erases to draw lines as guides where each letter is located.
Tape each individual stencil to the door. If the stencils overlap too much, tape them one letter at a time. Before painting, be sure the door is secured in one position so it's not moving at all.
Begin the stenciling process. Dab the paint from the brush off several times before painting the stencil. Wait for each letter to dry before beginning the next letter.