:

I do it like this:

First I start with some base colors.

Then I add scribbles.

Then I add more scribbles, and maybe change the layer to overlay or something so it’s more translucent.

Then I blur everything. Or smudge it. Depending on what will look best.

And then I repeat, using a smaller and softer brush as I go. Until I get something that looks like this:

You can also add noise and blur it that way:

But I don’t like noise layers that much because the undertones are always changing, and it’s harder to color. I’d rather just paint the undertone.

That’s really it, though. It’s a controlled scribble.

I use the same technique for stubble, leather, and metal, too. Like a suit of armor? I do it the same way:

You can see my scribbles on Richard’s armor and his leather sleeve.

Hope that helps. ❤