Last Friday I was a cheerleader, but today I'm going to be a pedant and talk about craft again. That doesn't mean I'm not still High On Life and not still thinking that We Writers Are Superheroes. Because I am and we are. Just saying. Onward, though.
One of the things agents and editors go on about is "voice." Voice is mostly an undefined term, and possibly people mean a great many things when they use that word (I pause to think of Inigo Montoya in "The Princess Bride"). But I think that "voice" is mostly just the way the narration of the story works. How are we telling the story, as one person (the writer) to another (the reader)? Are we casual, formal, revealing, secretive, speaking like our reader or speaking like a stranger? What speech habits does our narration have? That's "voice," as far as I can tell: the style of narration, whether through a character in the story or directly from the author. So let's talk a little about narration, and how it ties to voice.
One thing about narration that we have to be aware of is that all of it should reflect the emotional tone of the story. You'll no doubt have descriptive passages, talking to the reader about places, things or characters in the book, and in these passages it's easy to withdraw into our authorial space and distance ourselves from the emotional lives of whichever characters are placed into the locales or action we're describing.
For example, suppose you have a character walking down a street in a big city. You describe the street as Stella (our character) goes along:
The buildings lining the avenue were modern steel-and-glass skyscrapers, reflecting each other over Stella's head, each side of the street seeing itself across the avenue. Workers in 15th-floor offices looked out and saw themselves mirrored sixty feet away, not really ever seeing the building opposite...
And stuff. Weak, I know, but it's early. Anyway, this passage reveals my own fascination with modern architecture and the phenomenon of curtain-walled glass buildings reflecting the facades of buildings across the street, but it's got nothing to do with Stella. As a narrator, I've withdrawn from the story and am just handing out some facts and observations that don't involve Stella, down there on the street between the shiny skyscrapers.
In character-driven narration, which is what this post alleges to discuss, these sorts of passages are written from a distinct point-of-view that come from the dominant voice of the novel. If the whole book is written in a distant, emotionless style like the above passage, then the above passage fits with the voice of the book. Which is fine, if we're writing a textbook. But if the voice of the book is not distant and emotionless (and let's hope it's not), your descriptive passages shouldn't be, either. When you withdraw emotionally from your readers, they return the favor and either start skipping ahead or start looking for something else to read.
So, you should tie your narration to character. What does the landscape have to do with the characters within it? Tell us that. Don't tell us your authorial impressions of objects, places or persons. Tell us what they have to do with your characters, what they have to do with the emotional lives of those characters. Have your characters drive the narration.
The street scene, driven by character:
Stella walked down the avenue. She looked up at the modern steel-and-glass skyscrapers around her, noticing how the buildings on each side of the street were mirrored in the glass of the buildings opposite them. If I worked in a 15th-floor office, Stella thought, I'd see myself when I looked out my window and maybe never really see the building on the other side...
We get the same physical details, but now they have meaning to Stella. We have put our character into the narration and are letting her drive the narration.
Remember that your POV character doesn't exist merely to give her perspective on the action and the conflict. Your POV character gives perspective on the entirety of the narrative. When you come across passages that seem cold or distant, don't let the first question you ask about them be "what's wrong with this sentence?" Ask yourself first if the passages are about your characters. The prose itself might be fine, or better than fine. What might be missing is an emotional connection between the prose and the reader: a character driving the prose.
I'll try to come up with some better examples, possibly from real books.