I recently read William Zinsser's book On Writing Well.
The author explains how to write clear nonfiction on any topic: personal stories, people, travel, technology, sports, and art. He also outlines the mindset and discipline required for good writing.
The book was first published in 1976 and includes many references specific to the U.S. and the English language, but I still consider it essential reading for anyone who writes nonfiction: blog posts, website copy, or even academic articles.
A few quotes from the book:
"Writing well is not a natural gift. It is serious work, where success depends less on talent and more on mastery of practical writing skills."
"Clutter is the disease of American writing. We drown ourselves in heavy constructions, needless repetition, ornamental phrasing, and meaningless jargon."
"Clutter is also the euphemism that turns a slum into a 'socially depressed zone' and a dump into a 'waste placement facility.' It includes absurd political correctness, corporate language that hides mistakes, and military language that sanitizes aggression."
"What is journalistic jargon? A world where leaders are always 'empowered,' aides are always a 'team,' events are always 'upcoming,' and everyone constantly 'bombards' everyone else with statements."
"'John noticed him' is strong. 'He was noticed by John' is weak. The first sentence is short and clear about who did what; the second is longer and structurally limp."
"Most adjectives can be removed. So can many adverbs. Writers often miss that the noun already carries the meaning, and then overload prose with decoration that adds no clarity."
"There is a modern habit of stacking multiple nouns where one would do (or better, one verb). Rain no longer 'falls' - we get 'precipitation events.' Let rain be rain again."
Similar principles are also promoted by Maxim Ilyakhov in his courses on informational writing and editing.