On June 26, 1956, C.S. Lewis replied to a letter from an American girl named Joan with advice on writing:

1. Always try to use the language so as to make quite clear what you mean and make sure your sentence couldn’t mean anything else.
2. Always prefer the plain direct word to the long, vague one. Don’t implement promises, but keep them.
3. Never use abstract nouns when concrete ones will do. If you mean “More people died” don’t say “Mortality rose.”
4. In writing. Don’t use adjectives which merely tell us how you want us to feel about the things you are describing. I mean, instead of telling us the thing is “terrible,” describe it so that we’ll be terrified. Don’t say it was “delightful”; make us say “delightful” when we’ve read the description. You see, all those words (horrifying, wonderful, hideous, exquisite) are only like saying to your readers “Please, will you do my job for me.”
5. Don’t use words too big for the subject. Don’t say “infinitely” when you mean “very”; otherwise you’ll have no word left when you want to talk about something really infinite

Source: C.S. Lewis, Letters to Children, p. 64

Every writer should heed this advice. Let me clarify and have a little fun, as if Lewis needs commentary!

1. The point of writing is to communicate. This is why it can be a good idea to have someone else read your words out loud to you. They may very well emphasize the words in a way you did not intend them to be read. Doesn’t mean they are wrong. It means the words can be read two different ways.

2. Lewis doesn’t want you to write blandly. You can use words that snarl or soothe. But words that obfuscate or adumbrate or are intentionally tenebrous should be eliminated.

3. Instead of “His intelligence quotient was off the charts,” you might simply write “He was smart.”

4. This is a principle of “show, don’t tell,” which works for both fiction and nonfiction. But be careful. If you tell everything, it gets flat. If you show everything, the work becomes unreadable.

5. I have no apprehension of Lewis’s assiduous literary reflections in point five. Or am I being a poltroon characterized by a hoity-toity attitude? Or maybe just exhibiting room temperature IQ?