Filtering.
It’s …. She saw the sparrow fly overhead vs. A sparrow flew overhead.
It’s… He realized he made a mistake; she wasn’t coming back.
Vs. He made a mistake; she wasn’t coming back.

(Using filters creates psychic distance- pulling your reader out of your story. )

It’s She held the teacup in her hand vs. She held the teacup. (Where else would she have it if she was holding it?)
Or She turned the doorknob  (OMIT) with her hand

Filtering is a TELL!!  … remember that old rule – Show don’t tell?
Or the frequently cited quote on this… “Don’t tell me the moon is shining; show me the glint of light on broken glass.” -Anton Chekhov

In first person, you don’t have to say What a pain, she thought. If you write what a pain, we know the MC is thinking it.
In third person limited, it’s the same. You don’t need to tell us the person is thinking or realizing, just put it into the narrative and reader will realize its your POV character (or narrator in omniscient) coloring the story.

To me, this concept has given me a lot to work on, but it made my writing clearer. I am still learning to use this idea and apply it to my writing. Maybe it can help you too??
Tip: google “writing and filter words” for a list of these. See what it can do for you!!!

Disclaimer: You don’t need to get rid of all the filters, just play and see which ones you need.