I think that's the one thing all artists wrestle with... knowing when to stop and not overwork the art.
As I work on this latest colored pencil piece, I'm reminded of that. I have the hat details sketched in on the upper left ever so lightly, but when I look at the art, especially when viewed from afar, I'm loving the shape of the undefined, unfinished hat. I'll finish the ribbon around her neck, and finish out the braid along the trim of the hat, and then I'll be done. I think it's dramatic and strong this way.