Dean Wesley Smith gives Heinlein's Rules of Writing:
1. You must write.Read more of Dean's article here: Heinlein's Business Rules
2. You must finish what you start.
3. You must refrain from rewriting except to editorial order.
4. You must put it on the market.
5. You must keep it on the market until sold.”
Then he said, “The above five rules really have more to do with how to write fiction [...] but they are amazingly hard to follow — which is why there are so few professional writers and so many aspirants, and which is why I am not afraid to give away the racket!”
I found these rules and followed them when I got serious about writing in 1982. So did my wife before I knew her. So did so many more of my successful writer friends.
As Heinlein said, the rules are amazingly hard to follow.
And for those of you who are looking for a secret to making it as a professional writer, Heinlein put it right out there in 1947. And it hasn’t changed, unlike most everything else in this business.