Write mostly in the active voice rather than the passive voice.
“Active voice” means that the subject of the sentence performs the action. “Passive voice” means that an action is done to the subject of the sentence. Active writing is much stronger than passive writing, which is why teachers prefer it in most cases.
These passive sentences:
My tulips were destroyed by hopping rabbits.
Ralph’s brain was eaten by aliens.
could easily be rewritten in the active voice:
Hopping rabbits destroyed my tulips.
The aliens ate Ralph’s brain.