One has to be prepared to "let go" of part of a picture........this isn't always easy to do, especially when you have slaved away for ages on the image - but if the end result is better, it is worth doing.
When I was doing a whole series of "dancer" paintings, I painted this particular scene, putting together an image from several of my photos. I was never very happy with the figures on the right - they bugged me, no matter how much I tried to settle to them:. I did not like the positioning of the dancer bottom right, and I was never happy with the overall balance of light and dark shapes.
Cropping is perhaps a rather drastic way to "correct" an unhappy picture, but it can produce good results. Finding new images by cropping feels rather creative, actually, and quite satisfying. From a larger picture, particularly one that you feel has failed, or doesn't meet your expectations and doesn't please your inner taskmaster (that little demon sitting in our subconscious minds), you may well find more than one alternative solutions; more concentrated, intimate compositions, with a better balance of shapes and tones.......as I feel I did with this crop: