I have been working on trying to get the continents placed with rough edges. Been using some great tutorials that help a lot. Pretty happy with the way it is coming along but not sure about the edges of the disc still. I don't want to use the same method as the continents but I need to figure something out. I might look into some old maps that depict the edge of the world and see how they stylized it.
I am also trying to figure out how I am going to do rivers and mountains. I like the idea of using Wimble to create these features and then using map brushes to recreate the mountains with the rivers from wimble but I need to figure out the settings to use to get something I am happy with.