Here’s one I’ve noticed lately. It’s the practice of imparting important plot information to the protagonist by means of some vaguely supernatural, poorly characterized force. You know, “when she spotted the mysterious stranger, she was overcome by an instant feeling of dread,” thus informing her that he’s a Bad Guy. Or “I don’t know why, but I’m certain that we need to head west”.
Like many entries here, when it’s done properly, it can add to an atmosphere of mystery. Stephen King does this a lot, and he often manages to do it right. However, it can just as easily be the result of lazy, lazy writing. A lot of times, it’s “I can’t be bothered to figure out a logical way for my character to learn something important, so I’ll just say that they know it ‘somehow’”. I was reading something not long ago that did a TON of this, but now I can’t put my finger on what it was.
I guess I just remembered it from somewhere.