| You definitely need to lay out some idea of the game world you are trying to create, and the "feel". Gritty and real? Utterly fantastic and lighthearted? What's the history of the world, what themes does it contain, who are the major inhabitants?
Tolkein started with a world and wrote a story that occurred in it. You might want to try the same, to a lesser degree.
I might take a crack at some concept art but I would need a comprehensive idea of what you were shooting for. | 