While drawing Grog Strongjaw, I instagramed photos during different stages of drawing. Here's some insight on my process:
After sketching the whole image in blue pencil, I start to render the drawing with an HB pencil. With the blue pencil I work more on the shapes letting the lines and shapes overlap not worrying about value or texture.
Partially through rendering, I usually start with the characters face because if that isn't right, I will probably not like the rest of the image. Switching off between rendering with pencil and eraser stick (Tuff Stuff Eraser by Papermate) I build up values. I use a piece of wash cloth to smooth out rough gradients to be smooth.
Closer to the finial illustration, I like having the color pencil show through the finial drawing. To get tighter lines and texture, I'll use mechanical drafting pencils to build up the forms.
And thats a little insight to my work method.