Treasure Island began with a map that Robert Louis Stevenson sketched for his nephew on a rainy day.
Dinotopia also began with a map—though in the first map I called the island “Panmundia.” Once I had an idea of the overall shape and the kind of physical geography I wanted for the island, I sketched the island quickly in markers. The mountain and canyon relief is accentuated by an imaginary light source from the from the upper left. The original painting, below, was rendered in oil on illustration board.
It’s a good idea to add more place names than the ones you’re planning to use in a given story. This gives the feeling that the world exists beyond the boundaries of what you have revealed so far, and it also sets the stage for sequels.
In the most recent map of Dinotopia: Journey to Chandara, drawn with a dip pen in a mid-19th century style, I added dozens of new town names. More about that process at the previous post on "Place Names."