[header] How to create a fictional world from scratch [title] Determine the atmosphere and weather of the world. [step] Is the atmosphere similar to earth, where the inhabitants can breathe in the air comfortably? Or is the atmosphere more gaseous or toxic, similar to a planet like saturn? Describe how the atmosphere looks, smells, and feels. [substeps] Consider the weather. 
Is it the same in every part of the world? Is it warmer or cooler in certain spots? Does the weather change daily? Weekly? Monthly? [title] Identify the location of the world. [step] Specify where the world is located within the larger universe.