1. Mind the sun: Don't focus directly on the sun. This will fool your light meter and put your photo in danger of being overexpose. Instead, shoot a little above or below to adjust for shadows and light in other parts of the picture. You can also choose to avoid shooting the sun altogether, instead focusing in on foreground images while taking advantage of the sunset-colored sky.
2. Light Metering: If you under-expose your photo a little (maybe two stops at the most), it will highlight the colors of the sunset. A little lightening of the darker spots of the photo in Photoshop is not cheating. You can also choose to stick with a silhouette look for your foreground subjects. While its not a great rule to live by, under-exposure is better than over-exposure because at least in editing mode, you can lighten up a dark spot and find some hidden details, but you can't make something out of nothing in a bright spot.3. Avoid AWB: Take your camera off auto-white balance mode. If you stick with AWB, you could miss the natural gold tones. By using the "cloudy" or "shade," which bump up the warm tones, giving you a softer, yet perhaps mysterious picture. This all depends on how moody you want to be with your photo.
4. Framing: How you line up the sun in your photo really depends where you're standing and what's surrounding you. Sometimes framing the sun in the center works, but not always. Try moving your frame around with the sun in different spots, framing it around foliage, mountains, buildings, whatever. But a 4x6 picture with a sun in the middle and not much else can get pretty boring.
5. Hope for some clouds: While the sky isn't as bright as midday and won't wash colors out so easily, clouds can add natural texture and vibrancy to a sunset photo. Obviously, you don't want to shoot on a day with a lot of clouds, thus there will hardly be a sunset. If a cloud is in your way, either move yourself and your camera or wait for the cloud to pass. Clouds even tend to turn a golden color about 15-30 minutes after sunset, adding an extra layer to the photo.
6. Use a tripod: If I haven't said this enough times, I'll say it again: get ahold of a tripod. They're are some cheap models on the market and if you're serious about your photos, you'll get one. Not only will it reduce camera shake, giving you more control over aperture and shutter speed. With a longer shutter speed (say a half-second or longer), you can capture more details and light into darker spots of the frame.