As I am becoming old and must pass my knowledge to the new generations, I wrote this little 29 pages long scripture trying to describe in details my coloring technique - finally a Flash version for DA :3
Though I avoided going into details such as light color variations, backgrounds and texturing.
I must accentuate that this is NOT a tutorial where you repeat something step by step, this is just a description of the possibilities and you'd probably have to read this lecture several times and
make sure you don't skip anything.
Also I must say that this scripture is NOT entertainment. The actual entertainment will begin only after you eventually master this technique

A collection of artworks created using (more or less) this technique can be found
here! :3
Edit: More than 3 years passed since the Coloring Technique tutorial was published and now I sadly don't have enough time to update the collection or support this tutorial, sorry!
FREQUENTLY ASKED QUESTIONS:
Q: Will this tutorial work for Photoshop Elements?A: Reportedly, yes. People mentioned that it works in Photoshop Elements 3.0, 4.0 and 5.0, so it should work in 6.0 and later as well.
Q: There's no Select > Load Selection... in the menu in Photoshop Elements.A: You know when you have the lineart black'n'white on one single layer, not separated yet, try to Select > All, then go to Edit > Define Brush Preset, click OK to save it, then select brush tool, right-click on the canvas and select the last brush on the list, it should be your lineart converted into a brush stamp. Now just create a new layer and stamp your lineart onto it.
To change its color, right-click on the layer in the Layers panel, select Blending Options... then find Color Overlay on the left and select it, there you can choose a color for your lineart :3
Q: Where is the Burn Tool?A: To find the Burn Tool press Shift+O multiple times to rotate the tools until the hand icon appears. I'm not sure what that hand was actually supposed to do in the designer's mind 9_9 but yeah, it's the burn tool. To quickly select it again, simply press O.
Q: Where is the Smudge Tool?A: To find the Smudge Tool press Shift+R multiple times to rotate the tools until the pointing hand appears. To quickly select it again, simply press R. (Copying-'n'-pasting rocks :3)
Q: How can I clean up my sketch/lineart?A: Sorry, in this tutorial I assume that you already have a clean lineart somehow :3 I have no experience in cleaning up sketches because I don't draw on paper, myself. But try using the search bar on deviantART to find the tutorial that might help you.
If something doesn't want to work1. Re-read the text from the beginning without skipping anything. Most people who had problems with this tutorial, they actually just skipped this or that important part! If you get stuck in the beginning, try to perform these steps exactly:
1. Layer > Flatten Image
2. Image > Mode > Grayscale
3. Layer > New > Layer From Background
4. Select > Load Selection (set channel to "Background Gray" and check "Invert")
5. Now you should have the running ants across the edges of your lineart, that is, all the black pixels should become "selected".
6. While you have the selection: Layer > New Fill Layer > Solid Color (select black color)
7. After you created the fill layer, the selection should be gone, now run Layer > New Fill Layer > Solid Color (with white color)
8. Drag the "white" layer under the "black" layer.
9. Delete "Layer 0" as you won't need it anymore.
10. Image > Mode > RGB
In the end you should get a picture identical to your original lineart, but with all the black lines separated from the white background, so you can insert color-layers under the black lines but above the white background. Personally, I've just recorded an "action" that runs all the commands above automatically.
2. Make sure you use Photoshop 8.0 (aka CS) at least. Photoshop Elements 4.0 and higher should also work, although I haven't tested that myself. In Photoshop Elements the menus are probably a bit different, though.
3. Photoshop has a nice help system with a searching engine, so whichever isn't working, just press F1 and use Search, e.g. if you don't understand gradient maps, just type in "gradient maps" and read the articles -- the help section is designed to be user-friendly.
I've always been too destructive to my working drawings. "New layer from background" stumped me for a bit. I've always just double-clicked the background layer to turn it into a "normal" layer. Load Selection is interesting. I've always used "color range" selection (this doesn't require making a "normal" layer out of it first). Also doesn't require flattening anything or converting it to greyscale. about 20% fuzziness is good and select part of the background to make the mask.
After selection is made, Hit "D" to get default colors, CTRL-SHFT-N to get new layer hit "CTRL-backspace" to create white layer, "CTRL-SHFT-I" to reverse selection, CTRL-SHFT-N for another new layer, then ALT-backspace to get black layer. Changing colors would require using the "colorize" option of the Hue/Saturation control. But if you're on a Mac, obviously a lot of this is going to be less convenient, since Macs, for some reason, leave out some very useful keys and mouse buttons. I haven't had much excuse to use Actions, but this would be a good one, and it makes it irrelevant how many keystrokes it takes. This should be very easy to adapt to things like Gimp and Elements.
Thank you so much for posting it!