When writing a screenplay, by writing story beats first, it helps you organize your thoughts into a more coherent form. Once you complete writing the story beats, you can then begin writing each scene for your screenplay. By following this approach, you will find that you have a road map to follow with respect to your story beats. So, much of your grunt work goes into the story beats, while most of your creative work goes into the writing of each scene.
Story beats should show each scene in brief form. They do not have to be written in perfect grammar. They simply need to be written down in order. Story beats can be looked upon as idea beats. You have an idea for a scene. What should take place in that scene.? “Oh, yeah, this, this, and this.” Bang! You’ve written your story beats for the first scene. A word of caution, always enter your scene at the last moment and get out of the scene as soon as you can.
For example, on page 1/minute 1 of my screenplay/movie, “The Caller”, I introduce the setting. I introduce the main character. I show what she does as a professional. I show how she acts and reacts around other people. Bang! I move to the next page/scene. The story beats are: Introduce the setting. Introduce the main character. Show what she does as a professional. Show how she acts and reacts around other people. Get out, move to the next page/scene.
Once you get some story beats down, you will find that ideas come up where you want to write more in story beats you’ve already written. So, do that. If you want to expound on the setting, e.g., then add to introduce the setting, behind the stage of a fashion show. Then, get back to your story beats for the scene on which you are presently working.
Writing story beats are refreshing and very helpful to writing a multi-dimensional screenplay, something for which every screenwriter should strive.