The sun can be a very tricky subject to photograph. It is best to take multiple shots at different shutter speed and aperture settings when attempting to capture a sunrise or sunset.
If you are photographing the sunset or sunrise reflected by water, you may have to compensate for glare, depending on the angle of the reflection. [Sunset photos]
You will have to take your shots quickly as your subject is short lived.
When shooting a sunset, try to frame it with clouds or some other background or foreground objects to give your photograph more interest.
A sunset photographed through bare tree limbs, or limbs with early spring buds, can be interesting and attractive. Try shooting the sun off center in the photo. In this case, the framing of your shot is as important as the beauty of your subject.
A telephoto lens can be an asset when shooting sunsets or sunrises, as you are shooting from a distance and may want to zoom in on your subject to make it appear larger.
If the sunset is a background for another subject, it may be necessary to use either the camera flash or an external flash to highlight the main subject of the photo. At this time of day, natural light is low.
Getting the best results for sunrises and sunsets will depend on practice and experimentation with your camera settings, taking multiple shots and the creativity of the photographer in choosing the best angles and framing for the photos.