Try Serif drawplus it's free that's what i used to make my profile picture.
I am almost positive the answer is light, but let me know if that is wrong
This is one GREAT drawing tip that I always tend to use.
To shade:- To make it look like the person has contour, you can shade it with the pencil, then, smudge the place shaded with your finger...(rub on it). We do this so that it could look like a shaded area, it will make it look fabulous!
Try to make it look different:- Don't copy anything anyone makes, try to make it unique by adding shades, cold and warm.
