Some rules of writing are repeated so often they seem like hard truths, full stops, rather than flashing warning signs. Here are a few rules that are often misinterpreted or misapplied.
1. All adverbs are evil.
I dare you to pick up a novel off your shelf and search for adverbs. You will likely find those telltale -ly words every page or so. The reason this rule is often repeated is because adverbs are misused by many beginning writers. An adverb may be the right word to use, and like adjectives, they have more impact when used sparingly.
The warning: Using adverbs can also signal lazy writing. Consider if an adverb is right for the sentence or if you can you use words that have more impact.
2. Kill your darlings.
Well, what if the entire novel is your baby? What if you love it all? This rule does not mean that you have terrible taste, but that you should not be afraid to cut anything unnecessary to the story. Knowing what's necessary is the key.
Is it safe to cut a scene if it does not advance the plot? Not always. A scene may show character development, ground the reader with a sense of place and time, set the tone, or reinforce the themes of the novel. I see examples of the latter more frequently in literary fiction than genre.
The warning: If a scene does not advance the plot, you may be info dumping or getting off track. You can avoid this by identifying the purpose of each scene. You may want to consider how these details can be incorporated elsewhere in the story, or cut it if it does not fit.
3. Show don't tell.
Telling is necessary at times. It's not all bad. When should you tell? Here are some examples: when something is not important enough to describe in full, but must be known, or to illustrate the thoughts or personality of a particular character. Here's an older post about 'telling' with links to a few good articles on the subject.
The warning: Too much telling makes for a boring read. Maybe you've written the skeleton of a scene instead of a final scene. When you slip into telling, it could also be a sign of info dumping, or throwing in too much backstory. Know when to use it.
4. Write what you know.
You know more than you think. There are emotional truths, sensory truths, subconscious truths. We do not have to experience everything first hand to know. We can also learn from others, or do research and come to know. Stephen covered it here.
The warning: Maybe what you're writing doesn't feel real enough. How can you add more truth? Are you leveraging your experiences of the world to your best ability?
5. Avoid the passive voice.
Terri Giuliano wrote an excellent article on this: Two Rules Worth Breaking. It's well worth the read. In short, there are times when the passive choice is the appropriate choice. The article also talks about showing vs. telling.
The warning: Too much passive voice can indicate that the story feels lackluster. Active voice has movement and action. Double check your passive sentences. Is each sentence doing what you intend or can you write it in a more active way?
Those are just my top five. What other writing rules do you hear repeated too often?