Then my friend shows up with his world maps, his stack of binders full of information about everything from the technology to the plant and wildlife of his fantasy world, and several volumes' worth of information still in his head. Needless to say, I didn't do a whole lot of bragging about how developed my fantasy world is.
But, it did get me thinking about the importance of world-building as a fantasy writer. It's not enough to take your reader on a grand adventure with a wonderful cast of characters if they're doing it in a vague or shallow world. (You can click here to read my thoughts on the importance of descriptive detail in your writing.)
So fantasy writers, let's start at the beginning. What is the first thing you do when you start developing a new world? How do you get the process started? What methods work for you? What aspects of world-building are the most important to you?