A writer's words have power: lush, compelling words that create a reader's world have savvy power. Knowing how [and when] to be descriptive is what dips story into the well of one's imagination.
What sets writers apart from one another is the ability to be descriptive at the right moment. If all that's warranted is a brief narration of the opening scene - say in a story - being descriptive may send the reader's mind skipping ahead of itself too fast, or put the reader to sleep. One must be aware of when to use, or not use, description.
If however, the writer has trouble knowing when to use it, s/he should think "How would this sound the way it's written? What is the point I want to get across?"
They are questions one's mind must find an answer for. Say for instance, one is in the middle of a story about 2 men capsized from their catamaran; they have run out of food, and have very few survival skills. Writing "the sea was calm and salty" is not only bad description, it is cliche.
It is a story point where the narrator wants his/her readers to feel sympathy, hopelessness, and fear: properly placed descriptive narrative would do just that, as seen below:
Stan stood, staring at the water: the sea that had terrorized their hearts and fate the night before was a peaceful aquamarine by daylight, emerald where its depths dove for miles. Rocky edges stained the color of copper completed the scene.
"We're going to die in a rocky paradise," he told Holden without turning around. "How ironic is that?"
Because this type of story lends itself to many spots for description, one must pick and choose where and why it would be most effective. Always asking oneself what the purpose would be in a scene, comes in very handy. Say a writer wants his/her audience to know Stan is severely burnt. Would it be absolutely necessary for readers to know what the blisters looked like? Not really. Merely knowing him and his buddy are outcasts infers being burnt.
However, if Stan had a condition that was triggered by excessive exposure to the sun, that would be different: describing the blisters, and letting readers know Stan will go into anaphylactic shock soon because his allergy relief syringe and serum were gone, would cause fear and heart pounding suspense for the reader.
For some writers, asking that question to him/herself "What is the point I am trying to get across?" is a very helpful tool. It can help one create a laser-like focus on a story point, instead of going with the aura of personal excitement s/he feels.
Maybe the writer has personal knowledge of a scene, where s/he felt a certain way, and wants to get that across. But the "what am I tying to get across" question snaps the writer's mind back to the fact s/he is writing fiction.
Perhaps it's a literary novel instead, about a woman's loss of her father. She drives to a cabin they had used for fishing back when she was little, as a way of coping with that loss.
The writer would not need to describe the woman's car, nor the road or trees as she drove, but giving readers a sense of grief would be vital:
Marla entered the wooden cabin, now drafty; its walls looking ancient from mold of springs past: cracks surrounded casement windows, and leaves drifted like lost conversations, wandering, but left unsaid. The floor had tortured areas of wear - slugs slimed leisurely in one corner.
Back out on the pier her dad had attached to the cabin, Marla spied the boat they had once used. Turned upside down for whatever reason, the white paint was mostly gone. Its holes seemed to have been clawed there by some wild animal; the cracks oozing new algae.
Marla pushed her sunglasses up in a gesture Dad had been familiar with. She headed back to the car, all the sorrows from her father's memory and demise weighing heavily on her shoulders.
All writers should be picky: even choosy. Their own deepest critic when it comes to using descriptive narrative - it doesn't belong in every scene.
What is the point one wants to get across? That should be every fiction writer's mantra.
Fiction, whether in story or Novel form, needs direction and flow; a reality in the emotions it invokes, properly placed.
It's what makes the story compelling, flavored with anticipation, and swimming toward reader satisfaction. It's a wall that's hard to scale, that has treasures on the other side. It's passion, art, and writers who love what they do