25 Essential Questions to Ask Yourself when Worldbuilding
Setting is such an important part of story. Change the setting and you change the tone of the action. For example, imagine a breakup scene happening in a steamy sauna with just the two main characters versus it happening in a crowded coffee shop. They just feel different. (And maybe one of those is a more appropriate location than the other.)
Of course, the setting becomes a different beast altogether when you're writing fantasy. In fantasy, you're worldbuilding. Which sounds intense, because it is. Creating a world from scratch is an enormous task. You have to think about geography, culture, history, and potentially, a magic system.
The good news is that you don't actually have to start from nothing. You can base your world, country or culture off of existing ones. For instance, in Shadow and Bone, Leigh Bardugo based Ravka on Russia. You can see Russian influence in the Ravkan words she created and how Ravka is a cold, mountainous country, among other details.
However, it's also crucial to be careful when borrowing from other cultures and to make sure you're doing so with care and consideration. If you're going to take details from cultures that you don't have a personal stake in, please be sure to research them thoroughly and be intentional when you use them.
You can't research forever, though. At some point, you need to start writing, so I've written out twenty-five questions you need to get started with your world. You can get detailed as you write, but it's important to think about the broad strokes and jot down a few ideas first
Geography
What kind of climate does your world/country/state have?
Where is the nearest body of water to where your characters spend most of their time?
How does geography shape a country? (ex. If your country is by the sea, do most people make their money fishing? If it’s a cold country, are furs the luxury fashion of the rich, or does everyone have fur?)
History
What are common modes of transportation? Light? Industry/employment? Entertainment? Education?
What does a typical family unit look like?
What has driven change in the past 100 years?
Are there any historical events that directly affect the story?
Who has power? How did they get it?
Who is disenfranchised? How does socioeconomic status affect a person's standing in the world? And your main characters specifically?
What has caused controversy recently? Why?
Culture
Are there different species in this world? What are they? What are their key traits?
What kinds of technology exist in this world? Think medical, military, agricultural, textile, and architectural.
How is technology powered?
If there's magic in this world, how does it influence technology?
What is the dominant religion in this world? What are the minority religions?
Are there many languages in this world? Which is the lingua franca? Why?
Magic System
Is your magic system soft or hard? (See Sanderson's First Law of Magic.)
What can be done with magic? What can't?
What do people typically use magic for?
How does magic change or create conflict in the world?
Who has magic?
Are they born with it?
Is it considered good or bad to have magic?
How does someone's background (age, class, gender, etc.) influence the way they use magic?
What limits are there to the magic?
You can always go into more detail when worldbuilding. However, the aspects that will make your world the richest are the ways in which power, technology, geography, history and magic affect each other. If you have a solid base for each, you’ll be well placed to work out the way those structures are entwined.