I get inspiration from the real historical world than adapt to my world. If fantasy is my genre, then I will search for some medieval age events, to have an idea of how politics worked, important kings or queens, what happened to that place, which technology was predominant of their region. But of course, you don't want to say it all the information on the pages, for that, of course, your character lives there, so you have to show us how your world works. If an event is important, write about it. Let your MC breath his/her culture so we readers can appreciate his/her lifestyle.
