“How on earth do you paint your sculptures?”
I got the above question today, and I’ve gotten it a few times before about my painted critters. So I figured, hey, what’s a blog for, anyway? 
My latest finished piece being the Dragon Snail Kinoko, my answer is specifically in reference to him.
OOAK polymer clay sculpture, Dragon Snail Kinoko, by Erin 'Eirewolf' Metcalf.
I think the difference in the way I paint is that I do it in several layers. I don’t try to get all the color on in one or two layers. When I look at my own skin, I see that it’s made up of several colors, with some translucence between. I can see blue-green veins in my hand, for instance, because my skin is translucent. It isn’t just one solid color, even besides the veins. The palm of my hand has some pink, some yellow, some almost-brown, some nearly white, and then some blue-green where the veins are.
In the case of my critters, I usually lay down a base color first. For Kinoko, that was the salmony-orange color. Then I’ll do a few translucent layers over that, usually with similar but slightly different colors. Often I will not do a solid layer, but I’ll do sort of a dry-brush technique with small amounts of paint, not in long strokes but almost like stippling or dabbing randomly with the brush. That gives the sort of mottled look that creates believable flesh tones (for my critters).
The yellow spots were painted in a more solid color, to mimic the spots on the shell. Not much translucence there. I added translucence to that color for the brow region.
As for the midnight blue on his “foot,” that color is opaque up until it blends into the orange. Translucence was added for the blending, the throat, the beak, the horns, the crown, and around the eyes. I wanted a softer look there.
By the way, this piece was painted with Genesis Heat Set “oils.” These paints remain workable until you heat them. The technique would (in practice) be slightly different with acrylics, but functionally it’s very similar. For some examples, Mightier Than the Sword, Stormdancer, and Candy is Dandy were all painted with acrylics. The Wizard’s Foundling was painted with Genesis.
I hope I’ve explained it clearly enough. If not, please do ask specific questions and I will try to clarify!
Someone asked how I achieve transparency with the Genesis paints. I use the Glazing Gel for transparency, and the Thinning Medium helps with the consistency too.