Frick it's huge. I apologize.
I said I'd show a step-by-step some time ago, but I kept forgetting to take periodic screenshots whenever I drew. So finally I remembered. Here you go. I tried to show brush settings and stuff in there.
(Picture is Gintama :3)
Sorry, I don't want to do a tutorial or livestream, please don't ask x:
If you have other questions, ask in a comment and I'll answer it here in the description. Thanks!
Q: How long did it take?
A: Around 3 hours.
Q: What's the last step?
A: The grayish layer is a multiply, the blue one is an overlay.
Q: What brush sizes did you use?
A: I used a 4px for lineart here. The one for coloring just depends on what I'm trying to shade. I use the hard-edged round brush.
Q: What size is the original canvas?
A: It was around 4000x2000px.
Q: What program is this?
A: Photoshop CS3.
Q: Did you use mouse or tablet?
A: I used a Wacom Cintiq 12wx tablet here.
Q: How did you fill in colors? Do you erase the excess?
A: I use a combination of magicwand>paintbucket, and the brush tool. If it's excess skin color, I just cover it up later with a hair layer on top, and clothing over that even later.
Q: Why is stuff flipped sometimes?
A: I do it to check how the picture looks and sometimes because it's easier for me to draw facing one way or the other.