As for myself, I usually find that my first effort falls maddeningly short. The concept is there, but some zing is missing. Or there's a good punch line, but it's not delivered effectively. Or there's a certain flatness, a lack of tension, for which no amount of action and cleverness will quite compensate. Perhaps everything works, but there's a logic flaw--a glaring rip in the canvas that just can't be repaired.
Persistent cuss that I am, I usually work and work at such stories, often polishing the writing to a dazzling quality, adding snap and meaning to dialogue, bringing the world and scenes to life--and in the end find myself with a shiny silver goblet with a big dent in it.
The only way I've ever managed to fix the dent, is to stop trying, let at least a few months pass (less than three never works for me), and revisit the story after the love of the original concept, the burning inspiration that drove me to the page has worn off. Only this way can I manage to see past the blinders of the original vision. It is that, the love we feel towards our concept as if it was a living child, that makes it hard to make the changes that are needed.
But let some time go by, and now it's much easier to wield the ax, and do drastic surgery. Mind you, the patient does not always survive. Sometimes the cure is no better than the disease. But at times the distance I've acquired helps me break the boundaries of the box of my original story, and let it grow and become what it should be.
