Here are two sentences:

A. The man stood in front of me holding the gun.
B. The veins in his neck bulged as he stood half-turned toward me, the gun lying across his open palm.

These are both fully functional sentences. Both are true to the author’s intent. The basic action is clear, the threat is easily identified. But what makes sentence B so much more interesting? We see that the man holding the gun is under stress and his body language suggests that he is about to make a move – toward or away from using the gun. Sentence B is pregnant with possibility. Sentence A is too, but in a one-dimensional way.

We could end the blog post here. All of this is true and good, from a craft perspective.
However, a reader is hopefully going to pick this story up one day. Why is sentence B better for them? Because, there is magic in the detail. Such specifics earn your reader’s belief. Readers believe a narrator who sees much. As readers we trust the story teller who has a grasp on the intricacies of what is happening. The better the snapshot the more wholly we will invest in the action that is taking place. And the more we know, the more we want to know. And we turn the page.

So pick your specifics thoughtfully. Be accurate and concrete. Do your job. Your readers will happily follow.