kill one's darlings

Etymology
A piece of advice to prospective authors that they must kill their “darlings”, i.e. suppress overuse of their favorite expressions, tropes, characters, etc. Often attributed to (1897–1962), but already expressed earlier by  ; more recently popularized by.

Verb

 * 1)  To destroy things or characters, particularly in art, of which one is fond, and thereby conflicted about.