When I was starting out, I used to block in a base colour, slapped some black on the dark and some white on the light side and blend it, all at 100% opacity, of course. Blending a cel-shaded picture however looks terrible, so: Use plenty of colours. Paint, and don't let some buttons in the toolbox dictate your work style. And stay away from the airbrushes for shape defining.
"Ranarh's tiny tips" is a collection of iddy-biddy tutorials, each containing small bites of advice anyone can chew, aimed at beginner's level artists. They are not software-dependent. If there's a problem you have, something you feel someone should finally explain, or are just curious what I have to say on a particular artistic issue, feel free to tell me.
You'll find the whole Tiny Tips Collection, plus some full-grown walkthroughs in my tutorial section
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