This is a really simple trick that can help to give landscapes a softer, more atmospheric quality. Simply lift the black point so that there are no completely black pixels in the image. This opens up the shadows, and reduces contrast in the deepest tones. You can matte the blacks easily with the Curves command in Photoshop or the Curves Panel in Camera Raw and Lightroom. The bottom-left point on the diagonal curve line controls the blacks: lift this up slightly to set a lighter black point.