you should check out my work and jacob "unflown" covey if you want to see 3B posters. there are lot's of other folks who have done 3B posters, too. but, the two of us have the biggest concentrations here on gp.
So much I find so incredible on this one:
Choice of image (where the hell do you find something this cool???)
Knowing when to stop to retain the spontaneity of the piece
That last thing is something I strive to be better at. Note to self.