I learned a nice little technique today called shell texturing. AFAIK, it's an old method of creating grass and fur, but it can be used for other things as well.

The basic concept is to texture a flat plane with dots, and then repeatedly duplicate that plane on top of itself. The dots piled on top of each other appear to merge into long strands.

I've seen a few Japanese modders using this technique. From Software also used it to give Crossbreed Priscilla in Dark Souls her fluffy appearance.

Here's how it looks in Blender:

And in Skyrim & Dark Souls: