There’s more to good writing than avoiding common mistakes. Many people think that grammar consists of negative rules. It doesn’t, but it’s as well to conform to the rules most people know – mainly because if you break them, “people will write in”.
There’s a lot of writing advice on the internet – much of it can be ignored.
Avoid Alliteration Always. Not always – it can be effective: “I dodge your dawdling and aspire to avoid your toes” writes a wheelchair user. It’s unconscious rhyming that makes me flinch: “She was told to hold the item of old rolled gold.”
Avoid clichés like the plague. If you must use them, get them right. Don’t confuse “silver bullet” with “smoking gun”.
Ignore the people who tell you to “Take a cliché and give it a twist!”.
Use the vernacular. That means everyday speech. Avoid current slang your readers may not understand, but there’s no need to stick to the style of a university essay or company report. Write as you speak.
Parenthetical remarks (however relevant) are unnecessary. Parentheses are often necessary (and useful), just don’t shove in a long parenthesis between parts of the verb, or between subject and object.
It is wrong to ever split an infinitive. Sometimes there’s just nowhere else for the adverb to easily go. Are you going awkwardly to avoid the problem? Sometimes avoiding the split makes for an uglier – or even ambiguous – result. For many, though, avoiding split infinitives is the Number One grammar “thou shalt not”, so it’s better to abide by it. Why not remove the adverb altogether?
Never use a preposition to end a sentence with. Maybe not “never”, but try to avoid doing so. Eschew this kind of thing: Many more people are doing research on not only their condition or disorder, but also the people whom they seek treatment for it from. (psychcentral.com. ...the people from whom they seek the necessary treatment.)
Foreign words and phrases are not de rigueur. If you must use them, get them right. But not everyone speaks a European language – try to find an English equivalent for louche, macho or Zeitgeist.
One should never generalise. It’s a good idea to be specific, rather than general. “Darcy leaned on the carved wooden Tudor mantelpiece while Elizabeth reclined on a brocade-covered Chippendale chaise longue”, rather than “the room was luxuriously furnished in sumptuous materials”.
Never use an Oxford comma. I think Jacob Rees-Mogg is trying to warn us against Oxford commas – a comma before an and. Sometimes you need a comma before an and, and sometimes you don’t. And nobody fussed about "Oxford commas" before Lynne Truss discussed them Eats, Shoots and Leaves (published 2003).
Much more pedantry in my book A Short Guide to Writing Well.