Nothing builds intricate worlds like the attention to detail given to the story’s geography. What makes a setting compelling is the effort that goes into creating elaborate planets that are logical and familiar in terms of geology, history, climate and all that encompasses the geographical nature of the fictional world.
The more variety and complexity a world has, the further it enhances the other elements in the story. Physical environments can affect the plot and character, and determine what social organizations, culture and belief systems populate the place.
Variance is important. You can’t just have a planet depicted as having single forms of environments. Entirely desertic, or forested planets make no sense. Unless it’s an airless or complete snowball world, any grassland planets, swamp planets, ocean planets, and even a completely urbanized planet packed would have different temperate zones. They would be colder at the poles, and hotter at the equator. Mountain ranges and oceans would make a difference. And if tidally locked, the climate should provide enough variation to create a complex ecological system.
Arrakis of Dune
Dune (1965) – Frank Herbert