Achieving a Sense of Depth

If you want to achieve depth in your landscapes, I suggest overlapping planes and value differences.

In this painting of a canyon in Turkey Run State Park in Indiana, the darker foreground overlaps the lighter, steep rocky wall in the distance.  The overlap and the receding values emphasize the coolness of the canyon before it opens up into the light.

A third way to achieve a feeling of depth is to have the distant tones become more cool as they fade into the distance.  However, this painting gets warmer in the background which opens up the vista.

Think of values first and color second.  Overlapping is a great tool to accomplish the sense of distance.