A good skill for any landscape photographer is knowing how to find lines and curves in the scenery, and work them into your composition.
Meandering streams often create nice S-curves that are pleasing to the eye.
This frozen stream we came across had a great S-curve that begins deep in the photo and spills out into the foreground.
The same is true for the C-curves you might find along the shoreline of a lake or pond. When placed properly within the frame, these elements guide the eye around the scene, and help bring the viewer into your landscape.
The orientation of lines, much like the orientation of the image itself, convey feelings that emphasize the theme of your photograph. Horizontal lines are good for expressing vast open spaces and tranquil settings. Vertical lines connote majesty and height. Diagonal lines are good for action and motion. The shadows of these trees are lines that lead your eye well into the photograph.