How to Do It:

1. Prepare early. The best time to shoot is before it gets totally dark. There is a narrow time frame at late afternoon when even the sky is still daylight it will come totally dark in the pictures. The early hours before sunset will give you time to plan your shot before the good light happens. Turn the lights on early, well before it gets dark. Depending on the geographycal place and weather conditions it may get dark at different times so you need to be prepared between 4:30 and 5 pm.

2. Compose your photo in such a way as to include as much sky as possible in the background. Shooting from a low position can help. Even better: If you have your choice of shooting direction, shoot into the afterglow of the evening sky.

3. Once you get your picture framed, set your camera's white balance for "tungsten," as if you were shooting indoors without flash. All of those little lights are tungsten balanced. As a bonus, the tungsten setting will turn your afterglow sky royal blue once your light balances out. The sky will look great - even if it is a cloudy evening. And your lights will gleam crystal white. Or whatever color they are supposed to be.

4. A light (or reflective) foreground, like snow, or a puddle (or the roof of a car) can give nice foreground interest. See what you can find.

5. Use a tripod or a beanbag to steady your camera. You'll be shooting in the range of a quarter second to a full second at twilight. If shooting with a phone or PDA, use both hands to brace the phone against something solid.

6. Now, wait for the light to happen.

Shoot a test shot every minute or so. At first, you'll be exposing for the sky, the decoration and lights will appear unimpressive. If you can check the display of your camera after each shot to watch the Christmas lights appear to "come up" as the ambient light level goes down. You might not notice the ambient changes because the eye is constantly adjusting to compensate for the dropping light levels, but the changes will be happening nonetheless.
Somewhere in between sunset and full dark, the Christmas lights and the ambient light will start to mix beautifully. You'll have about a 10-minute window which will give you a nice series of subtly different lighting variations. Remembering to keep your camera as still as possible, shooting lots of frames through the mix light. Ones and zeros are free, so don't be stingy. You do not have much time. You can delete the duds (or blurred photos) later.