Hah, I had several shaders for rock cliffs, and chinese style limestone rock formations ,but they didn't work well with more "normal" mountains, like the alpine shader.
So I had an idea, just to add some simple Fractal ridge shader with two different sized input warp shader, with a lot of roughness, and use that as displacement on a simple alpine shader(with the minimum size is as big as 500 meters to give it a good simple base form) and I used one of my old rock textures on it and it looks pretty good! Perfect background mountains for Lord of the rings style wastelands.