Consider everything you write as a first draft. Write with the intention of changing things later, for cohesiveness, details, consistency, and sensory input. Can you see it? Can you smell it? Can you hear it? Who’s talking? Can you tell by the dialogue? Is your dialogue appropriate to the time period or geological region?
Does your plot make sense? Does your first page capture the reader’s interest? Is your word count too big? Too small? Do you have clichés? Are you telling, or are you showing? Does everyone fit well into the big picture? Are there too many unnecessary characters?
Once that first draft is written, that’s when the real work gets underway. To take a good idea and turn it into a great manuscript is more than just a one-shot deal. The best of writers go over their work numerous times, and it shows. Their work may sound like it just flowed out of them, ready to go, but you can rest assured they worked hard to get it that way, and it wasn’t by typing “The End” and closing the file.
In the construction business, they say, “Measure once, cut twice.” I think in the publishing business, they should say, “Write once, sell once,” because if your first draft is what goes to print, you won’t have any repeat customers. You might fool them once, but . . . well, you know the rest.