To do well composed landscape requires a curious man. You sit namely with multi-layer where it is important to have a good composition. Remember that you can get inspiration from the old masters such as Rubens, Rembrandt or Monet. The first and nearest is the foreground.
Here you can simplify with a blurred and / or dark foreground. Both the dark and blurry, will reinforce the perspective. Whether you have a fuzzy or a crisp foreground, keep it simple with few focus points. If you have too much to see your eyes are not led into the picture. Think of it as a prelude to everything about what is to come.
The motif is that you definitely what you should be in focus. You should place it in the middle layer, even if rules are made to be broken. You can also place multiple sub-motif also. If you have a bright motif attempt to have a darker background that can be contrasting. You may allow the subject to clarify an event, create life in the picture.
The background may often contrast with the scene. You may have a blurred background to the subject to show better. You can also let the sharpness spread throughout the image. It then becomes more important with a good composition. Imagine that the landscape will speak to the audience and give a number of dimensions.