Maybe the lenguage barrier is doing something here. I don't know specifically how to explain my method because my bad english. But about that "shape" stuff, I guess you are saying that I use predetermined shapes, for example: Faces or hands or something, nope, I make everything from scratch on all of my works. I cover around the lines with the Pen Tool in photoshop, then I put the color.
For example, the method I use, I draw the shapes, like i draw the head shape, and the eye shape, etcetera. those shapes have outlines, and i use Illustrator to change the thickness and shape of the outline.
but in another example, some people actually draw the outline itself AS a shape. so you have the shape that has the colour, and then a shape going around the edge that makes up the outline.