Well, actually  wolfmaster's question that made me wanna try to do this :)

I'm not good at teaching people, so you can just imagine how to do it your way.
[1] This is how my basic color looks like. Coloring it all using Polygonal Lasso, 0-pixel feather, and a Paint Bucket of Fill (Shift + F5). It could be terribly annoying to color, but once finished, it'll be easier to go to the next step.
[2] Let's pick a sample to shade. Since beginning, one intriguing me to show is this Lion's hair. So, let's put a new layer, lasso the area you like, you feel to be the darker color. Lassoing kinda randomly afterwards and locking it using Ctrl + Shift + Alt+ Click on the "Hair" layer does help you a lot.
[3] Make a new layer in case you're unsure, Lasso the area, lock it, and fill it with darker color. Voila, you've got 2-layers cell shading. You would continue to make darker color if you want. For me, if not extremely important, i limit it to two layers only.
[4] Apply it to other elements. Furr color 1, furr color 2, clothes, accesorries, bla bla bla.
[5] Okay all set, now we need a shining anime-like highlight. So, again, Lasso wherever you think essential to make a light, lock it, and this time make new layer OVER the outline layer. Fill it white.
[6] Almost set, eh? Good, now for a little more "brighty", let's make a new layer and brush it with around... 30 % white opacity in some points you consider "need" to be shiny. And you're done.

Let's do it again twice for another character, and we have the complete version

Thanks to  beruang-kun who provides his character Singa Buana, whom I consider very inspiring.

Anyway, I believe you have your own way to color. Any technique is good. So, keep it on track, mmkay?

I hope I could make another proper tutorial