When to stop?

Silver and Matisse Necklaces, 6 x6 " pastel on paper

As I get to the end of a painting, drawing or print there is is always that lingering doubt about whether I am 'finished' or not.  For me being finsished is about everything coming together in a balance of some sort.  Of course that doesn't mean I use a uniform approach.  I need to have enough interest to hold my imagination and expectation, but it needs to feel intentional and there shouldn't be anywhere in the image that is sticky for my eye, unless that's the objective.  So I look and look and try not to stepover the line between finished and stultified.  

I thought I'd finished Silver and Matisse Necklaces and then I realised that there was some confusion on the right side of the chain mail necklace.  I'm not sure if I rubbed it while I was working elsewhere or whether I just missed pulling it into focus.  I touched up a few other spots tand then the pastel was finished.