Your camera usually does a good job of exposing the sky during sunset, even in automatic mode. Keep the flash turned off and shoot at will.
Keep an eye on your shutter speed (if your camera shows it). If it goes below 1/30th of a second, you may need a tripod or some other steady surface to prevent camera shake. Activate the self-timer or remote control to avoid jiggling the camera when you press the shutter.
The biggest mistake people make when shooting sunsets has nothing to do with the sky—it’s the ground that ruins the shots. Your eyes can make out much more detail in the shadowy ground than your camera will. Therefore, it’s not worth trying to split the frame in half, composing it with the sky above and the ground below. The bottom half of your photo will just be a murky black blob in the final image.
Instead, fill your composition with 90 percent sky and 10 percent ground or water. This arrangement may feel funny—at least until you look at your prints and see how much more dynamic they are with this composition.
Many photographers make the mistake of leaving the scene right after the sun dips below the horizon. Hang around for another 10 minutes or so; sometimes there’s a truly amazing after-burst of light.