For some people creating new worlds is easy. For others it’s a bit more difficult. Here are a few things I’ve learned from experience:
Write more information about this world than you will use in the story.
Get out a notebook and write down as much about this world as you can: the landscapes, the history, the language, the climate, the people, everything you can think of. However, keep in mind that most of what you are creating will not make it into the finished product. People don’t like being bogged down by too much information. Nonetheless, it’s important that you have this background information so that it feels more organic. You don’t want the reader to feel as if you’re making it up as you go along.
Remember where you live affects who you are as a person.
Regardless of how you may dislike where you live or the customs you grew up with, it’s undeniable that where you are born affects your view of the world. The same should be said of your characters. For instance, people who live in less forgiving climates tend to be tougher than people that don’t. Think about your character and how their environment shaped their personality. Did it embolden them? Make them fearful? What side of the mountain they came from can make a difference in their development.
Travel.
Exploring new lands, tasting new food, and mingling with strangers is the best way to get your creative energies flowing. This is especially true when it comes to world-building. Traveling can broaden your horizons and inspire you to create new worlds that may nor may not resemble this one. You can look up photographs on the internet about certain landmarks, but it’s no substitute for being there yourself.
Read about other cultures.
This doesn’t mean you should directly or disrespectfully rip off of other cultures and their beliefs. However, exposure to new ideas (or at least ideas that are new to you) can inspire you to create your own. Study different religions and sciences. Read short story collections from other countries. Do as much research as you can about different environments.
Good luck!