
“I’ve always been fascinated by realism, and because of this it is really important to me that the base line-art sketch has got proper proportions. I usually use the old trick by putting a grid on top of a reference photo I’ve shot, and thenI copy the same grid onto a blank canvas and start drawing grid by grid from what I see on the reference photo.I make sure to keep the grid on….”
http://www.3dtotal.com/team/Tutorials_3/Equilibrium/equilibrium_01.php