Make sure the stove is turned off before you leave the house. Wipe your feet on the mat. Don't comb your hair in public. Each phrase may be familiar, but its emphasis is different: safety, hygiene, etiquette. Writing has some familiar phrases, too. Murder your darlings. Advance the plot.
An article in Slate traces the history of the phrase "Murder your darlings," to a Cambridge lecture contained in On the Art of Writing by Arthur Quiller-Couch (who? yes, who?). The word "darlings" refers to an ornamented paragraph or phrase of which you are particularly fond. You know what murder is. Details from "Lecture XII," dated Wednesday, January 28, 1914 at http://www.gutenberg.org/cache/epub/17470/pg17470.html.
Ann Patchett writes in This Is the Story of a Happy Marriage of omitting whole paragraphs, even chapters that she loves, if they do not advance the plot. This comes, it seems, from her days writing articles "when I watched my best sentences cut from an article because they did not advance the story." (from "Nonfiction, an Introduction.") When you have a word budget or a page budget, this makes sense.
In "The Getaway Car," Patchett writes, "Short chapters can speed the book along, while long chapters can deepen intensity." Keeping some of those paragraphs and chapters that do not specifically "advance the story" can do the same thing. She touches on the idea of time, but doesn't go into details.
I'm reading a new book, just published, Preparation for the Next Life by Atticus Lish (also the son of Gordon Lish, who edited Raymond Carver). It's a first novel, and it is beautifully written. Do all the chapters advance the story? Not always. But they do something else. A book is not only about plot, but about time. How long does it take to get to a certain piece of information? Do you make the reader anticipate, make the reader anxious, make the reader forget before you return to the plot or to the main character(s)? Lish is not only giving us a story, but he is painting pictures. And we are interested and engaged in looking at them.
Time is discussed in relation to book art, I think, more than in writing. Opening a box, untying a ribbon, or taking a paper out of an envelope slows the reading process. Introductory images, blank pages, title pages, all guide the viewer in and set the stage. When the main event begins, it may be broken up periodically and slowed with pockets or fold-outs, translucent pages, lots of words or none at all. The book artist can use time as a medium. Done poorly, these considerations and additions are "darlings," digressions, or distractions. Done well, these additions actually maintain the mood or add interesting information for thought. Maybe there is a way to use those "darlings," after all. (And I mean the ones we love, not the ones that have our Snoopy selves on the doghouse rolling with glee.)
I'm only halfway through Lish's novel, but I feel hooked, not only by the story, but by the way it is told. It travels from character to character, between past and present, with war underlying the telling. Stumbling blocks occur, the characters face difficult choices, there are moments that are ordinary, tender, horrible, or heartrending; but when the drama happens, it feels natural. You can feel the passing of time.
(Note: the cover photo and author photo in Lish's book are by Shelton Walsmith, a favorite artist of mine.)