Usually, as I’m nearing the end and an image is coalescing, I take breaks from it, stepping away, checking to see what needs tweaking—brightening, toning down, blending, or a complete restructuring. I might take a walk or have a snack. When I get back I’ll just glance at the piece, then away, to see if any area stands out as off, somehow. If so, I’ll look away, then back at it a few times to let that area speak to me and tell me what’s wrong.
Sometimes I just know what to do. If not, I go back to academic rules of color or value or composition to jog my vision, then correct. The tiniest thing might throw the whole piece off…a secondary highlight that’s too bright, or an iris that doesn’t quite line up. Or, it could be a whole area where marks seem stale or color muddy.
Rinse brush and repeat.
As the end nears, each mark becomes critical. At some point I’ll pick up the brush or tool, then set it down. If this happens more than a few times, I’ll know I’m done.
That does not mean that I could not still change something. It just means that the piece feels complete with itself and that if I make any changes I’ll be starting the process of creating a different sort of piece.
It’s that simple.