Give a stop or so. The easy way to get a breath-taking sunset is to cheat and use a sunset filter. Be aware that some people disapprove of being photographed - and may react aggressively if you point a camera at them. If you can, ask permission to take your shots. That way you get a more co-operative and often more relaxed subject.
Many subjects look better at night.
Choose a building today and try it. Try to take a picture with some depth. Choose a subject with the foreground a little dark and a good background. Then use a weak burst of fill-in flash. To avoid reflections, and give it a deeper colour, use a polarising filter apropriate to your lens.