Triplanar mapping is an automatic technique of generating texture coordinates. It is particularly useful for landscapes, rocks, trees and other objects with dense, organic patterns.
It is projecting textures from front, top and side, then blending between them.
Node setup: http://imgur.com/eXnezkB
Individual texture can be chosen for each direction (e.g. snow from the top, rock from the sides).
Usage: just use the Triplanar material. In the node editor, change Scale in mapping nodes and replace texture images.