Organisational Tips:
1. Check the sunset time and also check your gear (including that its clean and the battery is charged)
2. Sunset shots are often taken by water etc. so have insect repellent on hand
3. Find a good spot and then walk around, change levels to find the BEST vantage point
4. Arrive early to set up
5. Use a tripod
Camera Tips:
1. Pick your lens prior to arrival if possible - this way you have less risk of dust/sand getting in
2. Have your focal point preset so that yourcamera doesn't try and refocus every time you take your shot because this can be problamatic if you hit directly on light (but remember to adjust it if you adjust your focal length)
3. Check your horizon line is straight because it can really upset your image if it's not and whilst you can straighten during processing you may lose parts of the image you wanted to keep
4. Have something to add depth/ interest to the shot - a tree or people etc.
5. Personally I shoot in Aperture Priority mode - it works for me but remember to keep an eye on your settings to ensure you aren't receiving a hi/low reading and to adjust your aperture accordingly if you do see these pop up
One extra little tip that I find useful after any shooting is to return your camera back to what you consider your "standard" settings eg. Flick back to Aperture priority, flick VR back on and also autocus on both the lens and camera. Put your ISO back to your normal too. This way it is ready for when you need to pull it out next.