Friedrich's paintings commonly employed the Rückenfigur—a person seen from behind, contemplating the view. The viewer is encouraged to place himself in the position of the Rückenfigur, by which means he experiences the sublime potential of nature, understanding that the scene is as perceived and idealised by a human.Friedrich created the notion of a landscape full of romantic feeling—die romantische Stimmungslandschaft.
His art details a wide range of geographical features, such as rock coasts, forests, and mountain scenes. He often used the landscape to express religious themes. During his time, most of the best-known paintings were viewed as expressions of a religious mysticism.
He was one of the first artists to portray winter landscapes in which the land is rendered as stark and dead. Friedrich's winter scenes are solemn and still—according to the art historian Hermann Beenken, Friedrich painted winter scenes in which "no man has yet set his foot. The theme of nearly all the older winter pictures had been less winter itself than life in winter. In the 16th and 17th centuries, it was thought impossible to leave out such motifs as the crowd of skaters, the wanderer... It was Friedrich who first felt the wholly detached and distinctive features of a natural life. Instead of many tones, he sought the one; and so, in his landscape, he subordinated the composite chord into one single basic note".