Elmore Leonard famously advised writers to “try to avoid the parts that readers skip”. This is a definite risk when it comes to describing where your characters are, so listen to the master when dealing with setting.
I tend to underwrite setting, especially in the first draft during which we have agreed to “let it suck”. Have a scene in a library? As you work through the first draft, it will probably be enough to write, “Sharkey and Mack entered the library.” Get the story down now, add in additional setting details during rewrite.
But what is necessary and what is too much?
The golden rule, of course, is you must serve the story. Once you have your draft down, walk away. Go mow the lawn, change a diaper, have a catch with your kids, toil at your day job, take a walk. And in the back of your head, ask the following questions:
What does the scene absolutely have to do?
How can this setting help or hinder the protagonist, the antagonist, etc.?
What elements of this setting can be briefly mentioned to help establish mood, foreshadow events, or payoff some plot or character element?
Live the answers so they become part of your tale.
Then review the scene’s setting in terms of the five senses; how does it look, smell, sound, taste, feel? The more of these you can use, the stronger connection you will provide for your readers.
Let’s use the library as an example. If it is old and Ivy League that is very different than a smaller, more modern suburban town library, and that difference will an effect on the story. Look at the library in the film Seven and the one used as a central location for several seasons of Buffy The Vampire Slayer. They are fundamentally different, and create very different spaces in which to tell their respective tales.
How does the library smell? Think about how each the following answers fundamentally changes the scene: stacks of old books, a whiff of French perfume known to be worn by the killer, lilac air freshener, fire, hot buttered popcorn, way too much Old Spice, whiskey, the unmistakeable stench of decomposing human flesh. Now mix and match and you see how smell can shape setting.
Sound does similar work. How does each of the following hit a reader’s “ear” as s/he reads? The full quiet of many people working silently. The insistent tick of a clock. The quiet whimpering of one terrified person hiding in the stacks. Two kids giggling quietly. The sighs of quiet sex. The rustling of clothes being re-arranged quickly. The unmistakeable sound of a shotgun being locked and loaded.
What is the taste of a library? Stale air? Peppermints in a candy tray at the checkout counter? The copper taste of blood in the air? See how these few possibilities alter setting?
Feel is not in a character’s heart. Keep it exterior. The squish of a rug wet with blood. Thetexture of the old tome needed to save the world. The love letter’s delicate stationary in her hand. His rough palm on the frightened girl’s bare shoulder.
Get your setting down simply, then live in your setting as you go about your day. Finally, go back and fill in only the nuances that serve your story, and your setting will be an effective, crucial part of your story’s success.