Building a Fantasy Sandbox: Steps 7-10: Seriously This Time!

Okay, so now we have the basic layout of an area 150X200 miles, so, what's next?

7. Draw in mountains

Easy enough, we already said we wanted a volcano on the one "lair" island, and I pictured the lower island with a huge peak, with a lake below it, that had a river that tumbled off the edge as a waterfall down towards the surface, so I want atleast a mountain there too.

Here's what we come up with:


We put some mountains on the upper edge of the big island and at that point decide that the upper island actually broke off from the big one, so naturally the mountain range continues onto that island too. So I added the range for continuity and finish off Step 7.

8. Draw in rivers
9. Draw in hills using them to divide the region into distinct river valley

Again, I know I want that lake with the river, and I figure there needs to be atleast a water source on the big island as well. In my original cruddy paint sketch I drew the island in the upper left as having mostly hilly terrain with a river that comes from one hill and disappears into another, a good way to hint at a small underground network below the hills.
Once again, I start adding stuff:


Moving along pretty good now. What's next?

10. Draw in vegetation (swamps, forests, desert, etc)

Last but not least, forest, the desert I already did because I knew that was a whole island in of itself.
So I start plopping down trees:


As you can see the entire lower island and the non mountainous upper island are entirely woods, that means they're not settled human style yet (but that doesn't mean they're not yet settled) At the very least, the lower island makes for a good spot for the big island settlers to get lumber. The bit empty on the large island will be farmland, areas where the humans cleared out space so they could make food.

So that wraps that up, next up will be adding the places where living things... uh, live.
Of course, first we have to decide what living things exist on our world.