Frame Your Landscapes, Seascapes, and Skyscapes

Is the subject the sky above the land, or the land below the sky? If you have an interesting sky that you're trying to photograph, leave a third of the photo for the ground. If you are shooting terrain, leave a third of the photo for the sky.

Schonchin Butte with
the ground emphasized

Same shot, cropped to draw
attention to the sky

Again, that's a general guideline. There might be other things that change how you frame the shot—a large aircraft in flight might cause you to leave a little more ground out of the shot. A strange cloud pattern in the orange light of dusk with a flock of geese crossing it might do best with no ground in shot at all!