Dodge/burn (soft) - finger tool (hard) ! THE PERFECT WAY TO SKETCH in grayscale !

Hi !
Today I've test 3 new tool :)
I've never used dodge, and burn before !
I was thinking that was useless.. Well not really !
What I've learn ?
Simplifying shapes is the key, and 'O' key is for burn :).
(however, it can be really easy to lost focus, and at a certain point, it can be really difficult to do details, maybe to combine with another tool ? I'll test that later :-) )