Here are some images from the output of a new land mass generator we wrote for the Voxel Farm suite:
While the images are symbolic, they contain very detailed information about biome placement. Each pixel is approximately 2Km wide. You can imagine each biome type/pixel in this map replaced by a rich biome manifestation, which will provide elevation, erosion and other layers of detail. Rivers and lakes do not appear at this point because they need the final elevation. What you see here is more like a blueprint for where the next generation phase starts.
The challenge in this case was to make biomes appear in the right location. The method behind the images uses tectonic plate simulation for mountain ranges and a pretty cool humidity transfer system. I believe there is no other way if you want plausible maps. Just in case you want to see if the deserts and jungles make sense, note the wind in the three maps above comes from the south-west corner.
I will be covering how this works in my next post.