Contrary to what you may have read, the author mentioned the curtains for a reason and made them blue for a reason! Either that, or he was a crappy writer.
I’m interrupting my look at “The Cask of Amontillado” to make a digression. In the story, Fortunato wears a jester’s outfit with a cap and bells. The jingling of the bells asserts itself in the story with grim irony.
If your viewpoint character notices a detail, there must be a reason. The more the viewpoint character is focused on something else, like luring an enemy to his doom in some catacombs, the stronger the detail must be to impinge on his awareness. Also, details exist in an emotional context. A set of details in an effective passage may appear unrelated, but they probably aren’t.
Here’s an example from chapter ten of my YA novel posted on this blog. I was trying to capture Steve’s complete infatuation with Tess, employing every sense, arguably even taste.
“Can you smell the trees and flowers?” She raised her face to the sunlight and closed her eyes as she breathed deep.
“Yeah,” he said. He smelled humus and maybe dog shit, but he could catch the rosemary tinge of fir needles in the sun, and the bakery smell, like old cinnamon, of pollens mixing in the air. He didn’t close his eyes, though. He wanted to study her face, white as porcelain, like some elegant night creature, or a princess after a long stint in her tower. A shadow stretched from the side of her delicately shaped nose. He wanted to take her chin and tilt it into the light. A gust of wind freed a gleaming black lock and whipped it along the side of her face. Unconsciously, he reached forward with his injured arm in the sling, hooked the hair in his two exposed fingers, and brushed it back over her shoulder. She flinched, wary a moment, and then the hair blew back, across her lips. Far overhead a passenger jet made a tearing rumble, and she pulled the hair away, smiling. She went back to watching the mountain. “You have an awesome view, you know?”
“Far overhead a passenger jet made a tearing rumble” — this is the punctuating detail. It contrasts the fantasy-world imagery that’s always on his mind, so it grounds the passage in reality and yet communicates his ambition. Normally it’s something he wouldn’t notice, but it asserts itself here.
One way to keep dialog from just being a couple of talking heads is to introduce a background motif to highlight or contrast the emotional tone of the conversation, or even to become another member of the discussion. The bells that jingle take on a character of their own in “The Cask of Amontillado.” Lucius Shepard, in his long essay to his Clarion West students, gives the example of a tense conversation between a couple in a failing marriage that takes place in an echoey apartment. Their dog is walking around as they speak and the clacking of its nails on the linoleum and the sound of its drinking out of the toilet assert themselves now and then to underscore the tension.
As with any technique, use the background detail sparingly with conversation. As I said in the second essay on Poe’s story, the initial dialog between Montresor and Fortunato evokes the entire background noise and spectacle of the carnival simply by having Fortunato repeatedly shout “Amontillado!” as if trying to communicate his excitement against the noise. If you can get away with that kind of efficiency, do it.
I’d welcome examples of your own in the comments.