One of the most elusive and frustrating elements of photography is finding the right composition. Many otherwise good images are often derailed by poor compositional choices. There are several primary rules of composition to be aware of, and by being aware of them, and then combining them, you can give your landscape photos a real boost in terms of interest.
In this image, I had a flat gray mist killing any interest in the sky. But when this lone sailboat began sailing right at the edge of the mist, I began to see possibilities. By placing the sailboat at the intersection of the rule of thirds, and placing the horizon line at the bottom third of the image, I allowed the negative space to take up a lot of room. That negative space gives the boat a place to go, and keeps the interest squarely on the sailboat.
The first and most basic rule is the Rule of Thirds.