The Sense of Style is Steven Pinker’s guide to writing, and it is the model I try to write to here. He argues from how readers actually process text, not from rules handed down by tradition. The book runs in six moves.
Chapter 1 says writers learn by taking good prose apart to see why it works. Chapter 2 makes the case for classic style, where prose is a window on something the reader can see for herself. Its faults are signposting, hedging, apologizing, clichés, and zombie nouns, which are verbs embalmed as nouns. Chapter 3 names the curse of knowledge as the main cause of unclear writing. We forget what our readers do not know. The cures are to show a draft to someone like your reader, and to reread your own draft once it has gone cold.
Chapter 4 is about sentence shape. Let a sentence branch to the right, with the heavy phrase last. Put what the reader already knows before what is new. Use the passive when the doer is heavy or old news. Read a draft aloud, because a stumble in your mouth marks a knot in your syntax. He rejects the old advice to keep related words together, since it thinks in strings, not in trees.
Chapter 5 is coherence: keep the same subject running through a passage, and make the links between sentences explicit. Chapter 6 sorts real grammar rules from myths, like the bans on split infinitives and stranded prepositions.
Two popular tips need attribution. “Omit needless words” is Strunk and White’s. Pinker endorses it, then adds two caveats. Some redundant words earn their keep by steering the reader, and the rule is not an order to pare every sentence to the bone. Reading aloud, by contrast, really is his.
Outside this site I use the same three habits. For an email, I write the first sentence as the thing I want the reader to see. For documentation, I cut the signposts and define each term on first use. For a code comment, I say what the reader cannot see in the code, in one sentence.
Here I also borrow a few limits from Simplified Technical English, a controlled English written for aircraft manuals. I aim to keep each sentence to 25 words and each paragraph to six sentences.