Ideally, new parents could keep the lights off permanently and just wear night vision goggles as necessary. Think of how much you could save on your electric bill! On second thought, you would probably scare the dickens out of your baby, so there is no need to be that extreme. During the day, simply use a car seat with an adjustable visor that can shield your baby from any unwanted light. At bedtime, however, a little more effort is required to keep your baby “in the dark.”
In your quest to re-create the womb, darkness is a key factor for success. Remember that your baby slept in darkness for nine months. (Unless you are some bizarre freak of nature with a glow-in-the-dark womb.) Purchase room darkening shades AND curtains, since some light still peeks through the sides of the shades. A double layer is much more effective. Remove anything from the room that gives off light, including night-lights, clocks, and toys. If you think Bat Cave, you will be much more successful.
Many parents provide their baby with a night-light to somehow “protect” the child from being afraid in the dark. Being afraid of the dark is a learned, not natural, fear. Ironically, babies prefer the dark! Night-lights will distract them from sleep, especially when they stare at all of the shapes of light reflecting on the walls.
While your baby is sleeping in your room, use a low-wattage touch lamp on your night stand. When you need to check on the baby, you can touch the lamp on and off very quickly without fumbling for a switch or creating too much light. Touch lamps are also very useful during feedings, as you can touch the lamp as soon as you finish feeding the baby. It is easy to burp and rock a baby in the dark, and it helps them fall back asleep faster. If you leave a light on, your baby might decide it is time to “play” and coo at all of the interesting shadows on the wall. Even if you are normally a huge fan of shadow puppets, you will lose all interest after midnight.