Nothing too complicated for my part...
I used to draw everything on paper then take a photo to lineart from like, a few hours ago. Then today, out of intution, I tried using my tablet again, which "died" a year ago or something. I just re-installed the driver and MIRACLE ! It works. I still can't set the eraser and pressure on my pen, but well. Whatever. I can't config my buttons either, so I have to manually Ctrl+Z instead of just clicking a button. (That's annoying.)
So, now I keep the ideas in my mind and I begin sketching with my tablet on Paint Tool SAI frame by frame, in case I want to re-use or use slightly modified frames. (The great downside of sketching on paper was that I had to draw every frame again and again.) Then I go for the lineart, still on SAI.
Once I'm done with all the frames, I order them on a clean sheet on Photofiltre 7. That's where it gets fun ! Coloring time. My coloring is based on Hue Variation on shades of grey (I think I'm the only one who uses the Hue Variation on PF7...), then applying a darker version of the color I put to put a bit of relief. Screw shading. The skin is a special coloring, based on th same method but with different colors. That can give a fake sense of shading sometimes.
Annnd that's it, all I have to do after this is save the work and poof, done.