OK, sunsets. Big deal. We all take them; your mother loves them; so I put a few up here. I really don’t have much advice about how to take these things except for a few simple suggestions about composition. The most important is please don’t put the sun smack dab in the center of the frame.
If you really have nothing other than the sun and the horizon, then put the horizon as the lower-third border of your picture and shift the setting sun to the right hand top thirds border.
Use your zoom to get it as close to this as possible. The graphic here is nicely balanced using the rule of thirds and will look much more interesting and professional than putting the sun in the center of the frame. You camera will also meter more properly using this composition method.
If you put something else in the picture besides the setting sun and clouds like say your drunken mate, use the rule of thirds and place them to the side along the left-hand thirds border and again, not in the center.
It took me a long time to trust the rule of thirds as it never seemed correct to me to not put the subject in the center. After I stared at grids for a few months trying to understand something about composition, I started seeing this simple compositional approach in almost all media including television commercials. It is pretty common and it is common because it works. I dunno why, but it does.
Homework
If you want to totally geek out on this rule, Google “Golden Ratio”. Please be very careful with this and only take this in small doses because your head will explode. If it doesn’t pop with that, then try looking up the “Golden Mean”. Woah…… head rush!