Thank you darling, you’re the sweetest! <3 I suck at explaining stuff and my psd is a big mess of duplicated layers and filters so I’ll try to do my best. Please let me know if something is not clear enough :)
Idk if there are caps better than others to do this, but I think that the character should have an expression/ be in a situation that justifies the use of the skull. I mean, it might look weird on someone who looks happy and is enjoying whatever he’s doing. So, dying!Derek it is, resized to 500*281 px. I did some prep work on the screencap, which is essentially some curves layers to brighten it, a black and white gradient map and a levels layer for contrast. I wanted to have more dramatic shadows on the right side of his face and I did that with gradient fills layers set on soft light.
Then, the skull. I used this texture (from mellowmint’s anatomical textures pack) reversed it, resized it and moved it around so it would match his face. The warp tool (Edit>Transform>Warp) is useful if the skull doesn’t match your character’s face very well or at all (luckily I didn’t have to use it here). Play with different blending modes to see which one gives the best results, depending on your cap. Here, I set it on linear burn, 60% opacity. I didn’t want the skull to cover all of his face so using a layer mask (a+ tool, you can find a lot of tutorials to learn how to use it), I masked the parts and bits I didn’t want. The blending was way too harsh, especially around the nose; so, still on that layer mask, I used a soft brush with a medium grey color (it still hides stuff but less than the usual black) to make it more natural. If you’re not comfortable with layer masks you can also get the same effect with the clone stamp tool.
And that’s pretty much it? I merged and duplicated everything two or three times, set them on various blending modes and opacity, then added a few paper and grunge textures, and voilà!