If you are using the PMC Skin 3D thing, then using the "noise" function and turning the intensity up a lot if you want it to look realistic

I recommend that you do a simple shading then start to detail it more until you get to one that you like (that's what I did to create my hair shading style) another thing you could do is get inspired by other shading styles

umm... for me, th hair is the easiest part... i just recommend watching vids on hair shading '--'

hope that helps....

Not sure if this helps, but I would recommend watching a skin making video, speed coloring or something. You can search up the general style the hair goes with, for example, Mohawk I would search punk or grunge, something along those lines, and watch how they color! Make sure to make it your own too! :)

Tbh I'm not too good at shading hair myself, but I usually use different shades of the same color to make random stripes, and a lot of them. For a thick mohawkish hair, use the second layer of pixels (the hat) to your advantage, do a lot of it if you want really thick hair, maybe. I haven't tested that idea out but I think it will probably work.

Just do hair easy peezy

For the shape of the hair, the best way to find a suitable hairstyle is to experiment, slowly altering what you got until you've found something that fits what you have in mind.
As for shading, I'm not that good so I can't give you much advice

P.S. The hair on the character in the reference is likely going to be difficult to portray in a Minecraft skin due to you being limited in terms of 3d shape.

Use a second layer and try to paint them(hair)

Hey! Like somebody else said, your link doesn't work unfortunately.

But besides that, with hair I think what you need to do is take a look at skins that you like the hair of and try to mimic their shading style. For hair, using anywhere from 3-6 shades is best in my personal opinion. I always use 4-5 shades. You start with a color and make sure each shade of that color contrasts from the others enough. When you're shading hair, you can start by either putting down the lightest shade or the darkest shade first. I usually cover the section I'm working on, (like one side of the head) in a different color so I can see what I'm doing.

You want the lighter shades to be bordered by the darker shades. It's best to think about where your source of light is coming from and how that casts shadows. (The darkest shades will be your shadows.) I haven't seen any "guides" for it, but when you're doing hair the way you shade it is what makes it different and look like different styles. If I was going to do a mow-hawk, I would need three palettes. The palette for the skin of the skin, the palette of the "shaved" sections of hair, and the palette of the thicker mow-hawk part of the hair. Each of those would have 3-6 shades depending on your style (more simplistic, more detailed etc). I'd outline the shape of the hair, then I'd outline the overlays for the hair, and then I'd shade those sections one at a time.

The image doesn't work, try downloading it and uploading it to imgur, for some reason almost no images from wikia.com work on PMC

About your question, idk lol, I'm also bad with hair, maybe try looking at other skins