Repeat until it starts to feel done in your head. If it’s handwritten, type it into a computing device. When you are close to done, print it out on paper. Sit somewhere else with your favorite pen and edit your work harshly. If this piece is important, let someone else edit harshly.
I agree. Even if you write it on a computer, print it out and edit it by hand on paper. You’ll see things differently. Things that get missed on the screen. The writing will be better for having done so.