I remember a piece of writing advice from Brandon Sanderson (I’m not sure if he was referring to the words of someone else) which goes something like this. It relates to individual scenes in the story. Scenes should do the following.
- Progress the plot,
- Color the character, or help develop him further,
- Expand on the worldbuilding or setting.
Plot, character, and setting are the three aspects of the story that must be accounted for. Each scene should work on at least two of the three, and ideally all three.
I must note that drafting is not a good time to think about this. Consider the plot, character, and setting relevance of the scene while editing. Writing is difficult enough. Thinking about technical precision is unhelpful if it means the writing itself grids to a halt.