In short… there is no “one way”:
“There is no, do this, this, this, and this. Do whatever you need to do to write your story the best way you write it in your voice. Listen to how other people do it, and if something works for you, that’s great, but at the end of the day, do what you want to do. Do what feels right for you. There’s a lot of these aspiring writers and stuff, they’re always, “Tell me how to do it,” or “which rules do I follow?” Follow your own rules. I’m not saying you shouldn’t listen to others, you should, but it’s a process of just doing it. You’ll figure out your own way, if you just continue to do it. There’s no way one way.”
The above quote (with emphasis added by me) is from an excellent screenwriter roundtable posted to Go Into The Story.