on Copy Blogger:
“How do you know when you’re done editing?” is one of the most common questions I get asked from conscientious writers.
When you want to do a good job, you tend to obsess over your work. Since it needs to be “perfect,” it never quite seems finished.
So, careful and thoughtful writers have to develop another skill. They have to learn to let go.
To get past the goal of perfection, accept that your writing is never going to be perfect.