If you want to go as granular as your writing can get, think of it as a series of sentences. That's really all your story is—a long string of sentences. And each sentence will either propel the reader forward or make them pause and, if they pause for too long, stop reading altogether.
YOU CAN'T AFFORD A SINGLE BAD SENTENCE.
By "bad" I mean a sentence that fails to keep the reader's interest. So here is a trick to use.
Think of every sentence as a hook—a carrot, if you will. You're dangling a carrot in front of your reader's nose. You're saying, "Here is a sentence about something, but I won't tell you what it's about until the very end!" You can look at any of your sentences and identify one key word in each. Each sentence is about that word. So place that word at the very end to keep the reader reading.
This kind of sentence Robert McKee calls "suspenseful" in his book Dialogue. About 80% of your prose should be suspenseful to keep the reader engaged. The other 20% can be "reflective" (when the key word opens the sentence) and "balanced" (when the key word is in the middle of the sentence). This is the golden 80-20 rule, as you know. Of course, it's not really a rule, just a guideline.
I've written a blog post about these three types of sentences before. It lists examples of all three. Fun, right?
Now look at your sentences and see how easily you can kick up the steam.