Word choice is both incredibly simple and impossibly difficult. Every day we experience millions of words; we say them, we read them, we hear them on the radio or television, or in the songs played on our iPod. What's the way to get to the right word?
There are three questions to answer when you're starting a fic. The answers will be a huge influence on your word choice-- and they all influence each other. The first is:
How do I want the reader to feel about the story?
Is this humor, or tragedy? What's the tone: is it academic, serious, frivolous?
For example, I want the tone of this piece to be causal and informative. So for the most part I'm choosing simple words. I don't want to intimidate or seem to be talking down to any readers, and while I never want to 'talk down' to anyone, direct, simple language is usually just that-- direct and simple.
If one were writing a creative work that deliberately aimed for a humorous reaction, one might use intentionally hifalutin or carefully embroidered language to create a slightly ridiculous effect; the rather over-formal and affected voice I've chosen for this paragraph may well appear...a mite silly.
The second is:
When and where is this story set?
Do people generally speak formally, or informally? Do individual characters have speech patterns you need to follow or fake? (While I'm going to start with dialogue, you'll need to keep this in mind for question three, too, which talks about narrative.) In Keeping Up Appearances, which is set in England in the early 1990s, Hyacinth Bucket (pronounced Boo-kay) is a social climber with delusions of grandeur. She says things like this:
This is not the Chinese restaurant. This is a residential number and you are speaking to the lady of the house on a white, slim line telephone with last number redial facility.
Would you say that? Hell no. You'd say, "Sorry, this isn't the Chinese restaurant." Which is pretty much what she's saying, only she's saying it in the wordiest, most pretentious way possible.
Hyacinth's brother-in-law Onslow is a working-class shlub living off the public dole. Here's how he talks:
So then, this purser chap came up to the cabin and said were on the captain's table. And I thought, "Blimey!" I mean, you win a competition, you get a luxury cruise, and then they expect you to eat with the crew!
He uses short, simple words and lots of slang.
Fortunately, the best way to learn the right words in dialogue is simply to listen to (or read!) the canon.
The third is:
Who's telling the story?
If you're working with a first-person narrative, you'll use the character's own voice. Again, it helps to remember the tone you want the story to take-- for example, some narrators are inherently funnier than others, or if you want a story to sound like classic Sherlock Holmes, you have to choose Watson as a narrator. Here's an excerpt from A Study in Scarlet:
Worn with pain, and weak from the prolonged hardships which I had undergone, I was removed, with a great train of wounded sufferers, to the base hospital at Peshawar. Here I rallied, and had already improved so far as to be able to walk about the wards, and even to bask a little upon the verandah, when I was struck down by enteric fever, that curse of our Indian possessions. For months my life was despaired of, and when at last I came to myself and became convalescent, I was so weak and emaciated that a medical board determined that not a day should be lost in sending me back to England. I was dispatched, accordingly, in the troopship "Orontes," and landed a month later on Portsmouth jetty, with my health irretrievably ruined, but with permission from a paternal government to spend the next nine months in attempting to improve it.
At first glance, this seems pretty wordy. But Watson's language gives us an excellent picture of who he is and what he went through: Educated, precise (note he tells us the name and kind of ship he sails on), and intelligent. He uses some large words, but they're used in the service of giving us a more accurate picture.
Third-person narratives are trickier. Usually, you'll be using something in the vein of your own voice, and you should choose your words accordingly. When you were first writing, you may have spent a lot of time with a thesaurus on hand or in your search bar; maybe you still do! But using big words for the sake of big words usually makes just your work harder to read. Keep your words clear and direct; you're telling a story to a friend, and your friend could care less that you know six synonyms for "relax."
There are, of course, times when you'll want to break out the big words. Sometimes a big word is the only thing that feels right; sometimes you'll want to make an author or narrator seem pretentious or affected. And sometimes you'll want to give a person or situation special impact.
There were four young men at the table. The first was a blond in priest's robes who looked like he'd rather be anywhere else than sitting in our restaurant. The second had dark hair and green eyes; he was smiling, and seemed rather friendly. The third was clearly the youngest; he had an easy smile and light brown hair. I could see the glint of something gold in his hair-- some kind of crown, or headband?
And then there was the last man. His hair was long, brushing his shoulders, and a deep scarlet. His eyes were the same crimson shade, sharp and intelligent. When he smiled at me, his teeth were a brilliant white.
One of these men, of course, is not like the others-- the redhead has caught our narrator's eye, and simply using different language to describe him will tell the reader that.
Okay, I've answered those questions. What else will help me find the right words?
Remember to keep your words as clear and direct as possible. An important thing to keep in mind is the time-honored difference between the denotation and connotation of nouns.
The denotation is the literal meaning of the word, while the connotation is the emotional meaning of those words-- think of "house" and "home," which have similar dictionary definitions but very different emotional inferences. (Dionne Warwick got a big hit out of those differences back in the sixties!) Every word has an emotional connotation that you should keep in mind when writing.
Overall, if you aim for simple, direct and clear, you can be confident you're choosing the right words. Special circumstances, such as stories set in an earlier, more verbose time, will require you to reconsider your words, but you should still aim for clarity as your primary goal.
Literary agent Nathan Bransford on crafting a great voice
The basics of word choice from the University of North Carolina.