Pitfalls in writing

When writing, whether it is fiction or non-fiction, there are numerous pitfalls to avoid and what follows is just a selection of the most commonly encountered ones.
Clichés
Some authors tend to overuse clichés, although sometimes it is hard to avoid doing so, as in the following phrases:
caught like a rabbit in headlights
comfortable in his own skin
darkest before the dawn
sleep like the dead.
Overuse of clichés is bad enough, but where they get mangled or mixed up, the results can be rather tortuous:
But when boom went bust, the golden goose still ruled the roost. (Sarah Palin, Going Rogue: An American Life)
Overuse of favourite words
Many of us have our own favourite words and phrases, and authors are no exception. Novelist Tom Clancy loves the word “lit” instead of using the word “turn on” in Teeth of the Tiger, while novelist Dan Brown has a fascination with eyebrows, appearing on numerous pages of his book Digital Fortress: “arched her eyebrows” and “raised his eyebrows”. Well, it makes a change from a foot fetish.
Punctuation errors
Although the Oxford comma (sometimes referred to as the list or serial comma) before “and” / “or” in a list in text is not compulsory style, sometimes it is invaluable to use to avoid ambiguity or confusion, as in the following appearing in a UK newspaper:
Highlights of his global tour include encounters with Nelson Mandela, an 800-year-old demigod and a dildo collector.
How different it would have read with a comma before the “and”! The same could be said of the following in a US newspaper:
Among those interviewed were [singer Merle Haggard’s] two ex-wives, Kris Kristofferson and Robert Duvall.
Stating the impossible
Sometimes writers try to achieve the impossible in their writing:
It was one of those perfect June nights that so seldom occur except in August.
Their range was, within limits, virtually unlimited.
The dull-red mists seemed to flow together, enclosing the three sides of a circle. [The third author appears to have skipped some classes when studying mathematics at school.]
Stating the obvious
Some writers feel the need to spell out the most obvious concepts, which would be self-evident to the reader. Examples from published books, which shall remain unnamed to avoid the blushes of their authors, would be:
The sun rose promptly at dawn.
The patron licked his fingers with saliva.
Catholics as a rule avoid divorce – unless one of them dies.
(I am indebted to Ross and Kathryn Petras for some of the examples used above from their excellent book Wretched Writing: A Compendium of Crimes Against the English Language.)