When producing a project like TV series or movies, storyboards are useful that allow director and cinematographers to visualize their ideas into real things. As a game developer, you would need to learn this good tool to make your game view setting becoming easier on the process of developing.
Setting a storyboard in Unity is also an extension function under Cinemachine.
Once you add it, there will be a blank white covered the whole screen just like adding an image to UI.
Then you would need to import storyboard image ad texture, and assign it from the extension.
You can also adjust alpha channel to see the current camera setting.
When entering Play mode, you can simply checking Storyboard Global Mute to temperately hiding storyboard.
With your own storyboard(or from your art designer), you should be able to create an unique angle of camera to your game scene.