First of all you have to choose what you want photograph. What?! You may ask, but this can be the difference of taking a good picture. Leaving the viewer guessing by placing the hozin line in the center is not the best idea. You should place the horizon line in either the center of the top or the center of the bottom half of the frame. Here is an example below, in photography this is called the "Rule of Thirds".
In the above image I didn't have the horizon perfectly on the "Rule of Thirds" line but you get the idea as to where it is suppose to be located. The grass takes up most of the frame and the blocks and some interest to the picture. Since the blocks are right on the "Rule of Thirds" line it makes your eye wander through the picture.
So now you have the choice, what are you going to take a picture of, the sky or the earth. Neither is wrong but you shouldn't make your audience guess at what you want them to see and focus on.
Safety Notice: When taking pictures of the sun it is very dangerous to look directly into the sun especially if you have a DSLR camera with a telephoto lens. The worst thing that can happen to a photographer (next to death) is to become blind.
Now go out and shoot some beautiful sunset photos. Using the "Rule of Thirds" you can also avoid hurting your eyesight. Just remember, don't look into the light!
