Different words have different weight when they’re used. I can say it was a cold day or I can tell you that my breath hung, frozen in the air. Same thing, different weights, different feels. One is very basic and one brings an image or a remembered feel to mind. When it’s cold enough to see your breath, you know how that feels on your face, as the cold seeps into each layer of your clothing to needle at your skin. The word cold is functional but has no life.
If you write historical fiction, word choice is even more important. Language is a living thing, it evolves and devolves adding words as people create them and, when you’re writing about the 18th century, you shouldn’t use words that didn’t exist until the 20th century. Fortunately, there is an excellent resource right here on the beloved Internet for exactly that kind of research. Etymonline is the best site for figuring out if you can use the word malarkey or not in that 18th-century story – spoiler: don’t do it. Apparently, it’s even a Chrome extension now but I have not tried that service so I can’t speak to it yet.
Another thing to keep in mind is the baggage certain words carry. Some words and phrases have history that can’t quite be avoided but can absolutely be used to your advantage. Cold war calls to mind a very specific political atmosphere that lends well to descriptions of interpersonal relationships as much as politics. Epithets of all stripes carry baggage and while that’s occasionally useful, it should be used sparingly. Prodigal, holocaust, famine, Typhoid Mary, Trojan horse, and the list goes on. They are words with historical reference points that most readers have attached meaning to and you can use it.
Finding the right word for the feeling or imagery that you want to use can be difficult sometimes. The thesaurus is your friend. The Describer’s Dictionary functions similarly to a thesaurus but its format is a little more writer-friendly. If you need to describe a type of jawline and aren’t sure how, that’s the book for you. I have the older version.
There are words you should do your best to avoid – the nothing words. They add nothing to what you’re saying. Very. Just. Only. Really. I disagree about avoiding all -ly words but be judicious about them. If you’re writing an academic paper, by all means, avoid contractions. If you’re writing anything else, it will read strangely automated without contractions. When you think you’re finished writing, I do agree with Mr. King, a 10% word cut will tighten your language and make it so every word matters.