Just so we're perfectly clear- This is not makeup!
This is the result of almost an entire day's work. Done entirely in Photoshop using 4 source photos- 3 of different parts of a Zebra I took at Safari West, and one of me. Final image consisted of 7 layers.
A trick I used in this image is to use one layer for the black stripes and one layer for the white stripes. The black layer was set to multiply, the white layer was set to screen. If you leave them like that, then the two combined will not blend with the underlying layer. So next step is in the blending properties for each layer set the Blend if Gray sliders for each layer. Adjusting the blend if sliders allowed me to have the black layer blend only dark areas, and the white layer only to blend white areas, that way the two layers do not add up to opaque. Also with the blend if sliders, you can alt+drag the sliders to create smooth blended ranges, whereas if you just drag the whole slider you get choppy results.