Hone in this instance means to optimize, improve, better, enhance, refine.
I want to cover absolutely every aspect of my manuscript.
Because of this inter alia I have sought out several tool skill "screenwriting blue books" written by William C. Mantell. This is not because I envisage the story I have created to become a movie, but rather because of what can happen to a story when it becomes a script and thereafter, before it is shown on screen.
I am aware that a scriptwriter can live in a world where entire dialogue of a story can be wiped out and re-written. Even an actor can himself change dialogue.
As I start my very first edit I plan to be like a scriptwriter of my own work, a huge critic of every scene written, and to optimize my manuscript in the best way possible.
No pressure!!