How to Make a Map and Retroactively Fit the Biomes and Land Masses Into What You Are Redesigning

A world that is all kind of samey in terms of its landscape is not the most interesting thing. I really like writing big, lush worlds with a huge variety of different cultures. So you want to have sort of different canvases for them to develop in. And it's fun, too, that once you get to the point of dividing up countries or whatever you have,. Those mountains, those rivers, end up being natural boundaries or landmarks or borders between people and between what they understand and maybe what they don't know about yet.