One mistake I often used to make was over-precision in writing about the physical location of objects in a scene.
Robert put his keys on the end of the countertop. He dropped his pen. It fell to the floor and rolled three feet from his shoe.
The living room contained a love seat, two chairs, a shelf with books, and a side table with a lamp. The two chairs were placed to either side of the side table. The door was at the far end of the room and opened outward.
The first time a reader comes across something like this he may read it carefully in the expectation that for some reason it will prove important in a page or two. When it doesn’t he will skip any similar over-description the next time it occurs.
Far better to use vague terms for location and put in only a few important details. Precise physical relationships are unnecessary. The reader’s imagination will fill in the rest.
The punch landed right in Edward’s gut. The gun flew out of his hand and landed on the ground, just out of reach.
Jane’s bedroom was almost completely pink: curtains, carpet, even furniture. Stuffed animals covered every surface. On the pink bedspread was a single book: How to Commit a Murder.
For some reason the telephone tends to attract too much attention from writers. Everybody knows how a telephone works, there’s no need to attach elaborate description.
Don’t do this: The phone rang. John crossed the room and picked it up on the third ring. “Hello,” he said, cradling the receiver between his head and shoulder.
Better: The phone rang. “Hello?” John said.