I like to make a base layer that's completely covered. This keeps me from having color gaps later on (tiny, almost unnoticeable but there non-the-less). Often the base color has some bearing on the figure, but it doesn't have to. Sometimes it's easier to work with a color that's very contrasting to your background for this step.

I usually use the pencil tool to outline the whole figure, then use the paint bucket (anti-aliasing off) to fill the outline I've made.

So now all my base colors are done and on one layer. I used the pencil tool and paint bucket on each of his different areas, just like the previoius step. This just saves file space; you're welcome to put all the colors on different layers if you like.

Since my colors are separated by nice, hard lines I use the Magic Wand tool to select an area, then CTRL+J, which duplicates the selection and promotes it to a new layer.

This lets you work on one area independently of your main colors, and also preserves your colors on their original layer. So if you totally mess up, you can delete the new layer and start again with your original colors. I usually merge back when I'm done.

Don't forget to lock out your layer. That'll make for easier coloring, as you won't have to worry about coloring out of your preset area.

I'm going for the really authentic cel look, so I've used a thin brush (4px) to outline where my shadows will be. This outline is slightly darker (and greyer) than the actual paint shade will be.

This step is unnecessary, but I like the effect.

Using the paint bucket tool (anti-alias on), fill in the areas you've marked out. You may want to zoom in and spot check for small areas that may not have been filled.

Don't forget to line in the areas covered by black lines, or you'll spend forever trying to figure out why the bucket is covering your whole base color.

Realize that because you're working in Photoshop with the paint bucket you're probably going to want Tolerance between 3 and 30. This way your bucket won't leave fuzzy, partially covered areas where your shade meets your line.

You can also try double clicking the paint bucket on a fill. Your lines will lose some of their thickness, but it's not that noticeable.

Vector based programs (like Freehand, Illustrator and Flash) won't give you these problems. So instead of Photoshop you can try using one of those.

Or you can do your shade first, then put lines over it. (Which seems like a whole lot more work and not worth the effort.)

So alot of artists beginning to use cel-style often wonder where to put those shades. It's really puzzling to those used to soft style. (Took me ages to figure out, myself.)

It's best to place hard lines where you'd normally put a dark shadow. Simplify that shadow to one color instead of a gradiation, and don't bother with subtle shadows.

Alot of beginners also go nuts with highlights, and just arbitrarily place them on opposite sides of the shadow. ("Every shadow a highlight!")This can lead to a very odd and sloppy looking picture. Almost always you're going to want to concentrate on shades, and save highlights for shiney or reflective surfaces (eyes, hair, metal, sometimes skin, etc).

(As this quickly done example demonstrates) Notice also how the highlights take up almost or equally half an area of base color. You'll usually want more base color than highlight or shadow. Except in cases of extreme light (be it dark or bright), limit your extra tones.

Simplification is the key to an authentic animation cel look!

If you really want that extra tone, make another shade. Be careful not to go overboard with those as well.

Here's an example of an extra shade. I decided the lower right area (his left) of his shirt could benefit from a few darker folds.

My normal tendency is to put a shadow under the nose, seeing as it's normally a very dark area. In this case it's not needed, as his nose is so small and close to his face. A shadow would only obscure the nose.

Don't be afraid to stray from your normal methods; give yourself fresh insight and try different things with different characters and lighting styles. It leads to a nice variety and understanding of design.

Obviously I was going for a particular style with this character. But since Akira Toriyama has a whole lot more knowledge and experience with muscles, I can only try a hack imitation.

Anyhow, I've tried to make his chest and abs stick out a bit here, and I'll be going back later to add darker shadows and tweak the existing ones.

By playing with the way I did the shadows, I got a semi-shiney look to his horns. The gentle wavy lines combined with leaving a small area behind the shadow unshaded gives the impression of a somewhat reflective surface. (Think of the deep shadows and bright highlights highly reflective surfaces give off.)

Ahh shiney things. With jewels you have to remember (just like with eyes) the light shines through, so while one side will have that bright highlight, the opposite side will have a much less prominent but noticeable highlight. I've simplified it here by just adding another bright salmon highlight instead of a subtle shine-through. Also, don't forget that on the light source side, under the highlight will be darker than the rest of the jewel. (I've used black lines instead of color in this case.)

Here I like how the jewel holders and the buckle came out, but I don't like the overall look of the bands around his waist.

So on back to the bands and with a little simplification... that looks better. Had I limited the colors more, it probably would have turned out even nicer.

While my main colors are on one layer, I've not merged any of the new layers I've made. I like to leave my layers separate until I'm done, for easy tweaking in case I go back. (Yes, your file will probably get really big (especially working at 200+dpi, but it'll shrink dramatically when you merge everything at the end).

Don't be afraid to go back. Don't set anything in stone, especially while you're working. Personally, I won't leave anything set until I'm done with a file. I'm not big on going back and fixing once I consider a work 'done.' Instead, I prefer to note what I liked or didn't, and try to improve that with the next work. But that doesn't mean I won't change lots of things while I'm still working on a file.

Ahh the hair; a demon of it's own. I did each spike separately, with two things in mind: How much it sits up and how much shadow may be cast on it from another spike. And I kept the shadow lines jagged to better suggest uneven hair.

But the back of his head is looking flat compared to the front, so I'll just add some darker tones back there.

In keeping with the Toriyama style, I've left his eyeballs white and used just a light blue highlight on his eye instead of a white one.

With more complicated or elaborate styles you can really get into highlights and shadows all over the eye, but that's unnecessary here.