[header] How to write an alien sci fi story [title] Learn about the role of aliens in a sci-fi story. [step] Your alien sci-fi story could focus primarily on aliens and their perspective on the world. You may not have any humans in the story and instead, focus primarily on the alien point of view. 
Or, you may want to write an alien invasion story, where aliens invade the human world. [substeps] Some alien sci-fi stories focus on the interaction between humans and aliens.