Hang Roman shades from your windows and over the window on your door. Match the ones in the flanking windows, but consider choosing a complementary color for the one over the window in your door.
Hang bright, matching valences over both windows and the doors. If your windows and door are in a living room, match the fabric to the upholstery on the furniture. Valences won't keep prying eyes out of your rooms, though.
Hang decorative pendant lamps from tall ceilings above windows and the door. Keep the lamp above the top of the door. However, the lamps could hang below the top level of the window to add some decoration that can be seen from the outside. Add bulbs in colors other than white to jazz it up even more.
Place painted screens in front of the windows to block out most of the light. Look for something that mimics the color of your room on the inside and something that matches the trim of your exterior.
Press cling-stick decals to the windows and door to create a scene when holidays approach. Don't just place them randomly. Plan where each one would look best. With three large windows, you can tell a story in pictures with your decals.