If you take a writing class focused on editing and revision, you will learn certain classic tips. Common suggestions for improving your prose include:

Avoid wordiness: A wordy sentence example might be: “She was walking quickly towards the school’s library, but then she changed her mind and decided she might want to alter her course and go to the cafeteria instead.”

The sentence can be edited to be significantly less wordy. One example of a shorter version is: “She was walking towards the library, but she changed her mind and headed to the cafeteria.”

Avoid the passive voice. Change “The ball was kicked by the boy” to “The boy kicked the ball.”

Occasionally the passive voice might be required, but avoiding it tightens your sentences.

Avoid repetition. When you read a first draft, you might be surprised at how often you’ve repeated the same word. For example, you might repeatedly use the word “walk.”  

Maybe instead of “walking,” your character can “stroll” or “amble” or “rush” to their destination – or maybe your characters “walk” too often, and a change in action can be considered.

To add to the above common tips, I want to add an idea that was never presented to me the way I use it:

Any sentence that begins with “that is (was)” or “there is (was)” or “it is (was)” or “these are (were)” is an opportunity for revision. Your sentence can be less wordy and incorporate a stronger subject noun.

Examples:

That is the boy whom Sarah saw at school.

Revision: Sarah saw that boy at school.

There was a man standing at the edge of the field.

Revision: A man stood at the edge of the field.

It was a cold day with a lot of wind.

Revision: The day was cold and windy.

There were a lot of people watching from the bleachers.

Revision: A large crowd watched from the bleachers.

These are the days you will remember.

Revision: You will remember these days.

As  with any writing “rule” or “tip,” remember: No rule is hard and fast.

Consider songwriting. The hit Bangles song “Manic Monday,” includes the following line: “These are the days when you wish your bed was already made.” Prince wrote that song. He had a good reason for using fourteen syllables in that line. I am not going to argue with Prince.

Musicality makes a difference in prose sentences, too.

Generally, however, as you are revising, watch for sentences that start with, “That was” or “This is,” etc. They usually provide an opportunity to revise to a stronger sentence.