Know your characters well and the story will write itself.
I would say to get the character in your mind. Once he is in your mind, and he is right, and he’s true, then he does the work himself. All you need to do then is to trot along behind him and put down what he does and what he says. It’s the ingestion and then the gestation. You’ve got to know the character. You’ve got to believe in him. You’ve got to feel that he is alive, and then, of course, you will have to do a certain amount of picking and choosing among the possibilities of his action, so that his actions fit the character which you believe in. After that, the business of putting him down on paper is mechanical.
Source: Open Culture