I once found this awesome tutorial online that taught me how to make land and mountain texture. It involved something to do with clouds/difference clouds, brushing in white to raise land, and black to lower, etc., alpha channels, and the lighting effects tool. Using this tutorial, I made an awesome texture-map to overlay on my land. The result is attached. Basically, it involved the creation of a displacement map.

Here is my problem. I lost the tutorial. I can't find it anywhere, and I can't quite remember how to make it work right! No matter what I type in Google, I can't seem to reproduce the magical keywords that brought me to that tutorial. Does anyone either know of a tutorial on this site, or has found the tutorial I was talking about? I hope the attached image helps out in showing what I mean; it's hard to explain a process you don't remember too well.