Ok, so I'm writing a series of fantasy shorts in which there are many different regions and continents of the world. We have several southern, plain regions, coastal regions, mountainous regions, desert regions, and many different types of islands and the like. I've had no problem creating the world; it's the people and their racial diffences that I'm struggling with. In our world, there are many types of races and ethnicities, but I'm finding it hard to decide what to do in my world. I know that I want the mountainous regions to be inhabited by people somewhat like the Native Americans back hundreds of years ago, but other than that all of my different regions's people all seem the same. I want each of the regions to have their own destinct differences, such as appearance, language, and culture. Does anyone have any ideas or suggestions that may aide me?