Every day that you write, you make choices in your writing. What words you choose, when you end sentences and paragraphs, whether or not you italicize, bold, or underline words, and what grammatical structures you use all contribute to the way your manuscript comes out in the end. While the story you tell is important, these choices make up how you tell it and they cannot be ignored. After all, two writers may have very similar ideas for a plot but each will tell it in their unique way.
Time and time again, I come across some of these unique choices in the books I, myself, read, and if there is one thing I have learned from reading some of these strange choices it is to pay more attention to my own choices. I think three things (in general) should be said of word choices in particular in writing. I have written a post on lengths already which you can find here so while I do believe that the lengths of one's paragraphs, chapters, and sentences do contribute to the flow, diction, and mood of the book, it is the word choice and use of italics (and other emphases) I will focus on here.
General Word Choice:
Most commonly, word choice comes down to the choice between two common words. Most of the time, writers don't even think about the words they use in their manuscripts. I know this is generally how I, myself write, and honestly, it is how I encourage other writers to write... on the first draft.
On the first draft, it is important not to think too deeply about word choice. Much of the word choice errors that you might make on the first draft can be fixed later as you read it over. If you are like me and tend to write with the lingo of one country in one sentence and another in the next (New Zealand and the United States in case you didn't get that) you might want to decide which of the two you are using beforehand though to make it easier for the editing process. As I edited, I had to fix places where I used both "meter" and "foot" or "colour" and "color."
When you do get to the final draft, you will want to figure out what you need to convey with your word choice. Who is speaking? How do they speak? What knowledge do they have and how would they convey that?
For example, I have two characters that have chapters in their point of view. One is a criminal. One is a prince and guard. Obviously, you can expect that there might be a slight variation in the way the two of them speak. My mother has caught plenty of places where the criminal has used "do not" or "will not" instead of contractions. It is these small word choices that help to make your characters.
But more than that, what would your character know? What words would one character use that the other wouldn't? Don't have a character call a spider an arachnid unless they know a lot about spiders. Do have a character say the exact species of a spider if they are an arachnid fan! Don't use elaborate (and long and beautiful) words to describe things if the character was brought up in the forest. Do make your character polite and chivalrous with excellent vocabulary if they grew up in a castle.
One thing I also notice in books is the use of the less common word above the more common word. For example, I recently read Part of Your World (part of the Twisted Tale series) and found one exchange in the book to be particularly annoying. The most commonly accepted plural of "octopus" is "octopi" (though, technically, both "octopodes" and "octopuses" are correct). In the book, one character used the plural "octopuses" and another (after multiple paragraphs of conversation, no less) corrected them to "octopodes." One of the two characters was Queen of the Ocean and should have known the correct term so it was strange to see two less commonly used terms. This is not something I would suggest. If there is more than one term, use the most commonly used term.
Try to also choose your words carefully so that two words don't remain too close to one another. Something I had to correct in my book was my use of the word "criminal." I overused the word in many of my drafts and had to find synonyms for the word in the final draft to ensure that "criminal" was not repeated constantly throughout a paragraph. The same idea is visible in Part of Your World where the author notes "the heavy crown lay heavily." Please try not to do this. Perhaps not all readers will notice these mistakes but the ones that do will be frustrated by them.
Specific Word Choice:
There are also plenty of situations in which the word choice is more specific. For instance: should you use "food" or a particular type of food? "Shirt" or the specific shirt a woman of that time period wore? "Sword" or the particular part of a particular sword?
There is a time and a place to be specific and a time and a place to be simple. I have found that many books excellently describe the words they use and allow themselves to use more specific words throughout the books which gives them much more vivid description and action.
For example, Cursed uses terms like "crossguard" and more specific terms referring to the parts of a sword but they are used near the very beginning of the book in such a way that novice readers could gain an understanding of what each word means. This allows the author to then use the same words again throughout the rest of the book without explanation.
Shadow and Bone doesn't explain what some of their more complex words are (kvas, kefta, etc.) but the more they are used throughout the book, the more the reader gets a grip on what each one means. Shadow and Bone also does a good job of introducing only a few elements at a time so as not to confuse the reader with an abundance of new words.
Crazy Rich Asians uses a different method of explaining each of the different complex references to Asian culture. In this book, footnotes are added to explain the food, people, words from other languages, and more.
On the opposite side, the author of Red Rising, at times, introduces too much at once, not giving himself time to thoroughly explain each element to the reader and instead of leaving them drowning in the mess of worldbuilding that he has created.
My suggestion? If you don't have time to describe it, don't include it. I think Shadow and Bone does a great job of only including a few elements so that readers can eventually pick up on what they are referring to but I certainly prefer to have understanding right off the bat. And while the footnote style of Crazy Rich Asians certainly works for that book, I do not think it would work for many other books. My preferred style is something similar to what Cursed pulls off with the swordfight between Nimue and Arthur in the beginning of the book.
This swordfight defines the terms as they are included.
It doesn't mean the book says "a crossguard is the bar of metal at a right angle to the blade." Rather it makes it clear in the writing that this is what it is. I don't think you need to do this for absolutely everything. Shadow and Bone is a great example of this. But you can use this method to reduce the complex words you have to a minimum so that your reader can come to understand the rest.
The rule I use is, if I had to look it up, my reader will have to as well. I try to prevent that from happening. When I introduce Hope's weapon (the chakram), I define it as a circular blade. I define "poffertjes" as dutch pancakes and though I use medieval clothing, I don't use the more obscure words.
Though many of you may know the word "arboretum," here is an example of a direct quote from my book portraying the technique I like to use to define my more complex words. You'll notice I don't "define" arboretum but I do make it clear what I mean by the word here.
"This was one of many arboretums in the palace but most of the other indoor gardens were much larger than this one. "
It can be confusing to know where to put emphasis in a book. I don't know that I have read many books that go entirely without emphasis of some kind (usually italics, sometimes bold, underline, or all caps) but as you write the book you might find yourself having some difficulty deciding where to place that emphasis.
Personally, I only use italics. I find bold and underlining to be out of place in a book and my characters don't often shout loud enough that I feel their words need to be entirely capitalized.
The way I see it, there are to places that italics might belong. Some books have only one of the two while others (like mine) use both. First, I like to italicize the words that come from a foreign language. Particularly the foods that people might not recognize. I have mostly Dutch foods in The Criminal but I also use German, Italian and French inspiration in the books as a whole. In this book, the two main Dutch foods that appear are "ontbijtkoek" (a spiced rye bread often eaten at breakfast) and "poffertjes" (Dutch pancakes eaten with powdered sugar that are way better than US pancakes). I also like to italicize the "scientific" names of berries, plants, trees, etc. that I make up. So when I introduce the eterno bacca and another berry, it is italicized.
You often see this kind of thing in books with more cultural references like Crazy Rich Asians or More Than Just a Pretty Face where the words that people might not recognize (because they are in a different language or refer to cultural foods, traditions, or clothing) are italicized. I find this helpful. In some ways, it helps readers to find the words they could plug into google. In other ways, it helps them to understand I'm not alone in my not understanding!
But I don't forget to also italicize the words that need to be emphasized. This can be a little more tricky to figure out. You certainly don't want to overemphasize your manuscript. There shouldn't be italics in every second paragraph. On the other hand, though, forgetting italics where they should be there could mean that readers misunderstand the book.
I suggest, when you read through your book, you really think about each sentence. If, when you are reading a sentence, you naturally emphasize a word in your head, it is probably because it needs that emphasis. Try reading it without the emphasis. Does it have the same meaning? Does it have the same oomph? If not, totally add that italics!