First project ever so I'm a bit anxious, but here I go!

I'm currently DM'ing a campaign for which I'm still figuring out the background lore and geography as we go. The current working title for the world is "Aziz", but through some great coincidence one of my players decided to name his character "Aziz" as well. So I don't know if I'll be sticking with that name.

### Latest WIP ###
Click image for larger version.  Name: Azil resized.png  Views: 94  Size: 7.10 MB  ID: 111913

I started this project from the excellent Saderan tutorial (many thanks!). Thinking I wanted to print this in a high resolution on a large paper format, like A1 or something, I started a huge file, 11584 by 8192 px. This had some effects on the use of low-res textures.

Now, I know what you're gonna say, and I agree. The geography of this map is way out of whack . Part of the reason for this is that I only started reading up on realistic geography and rivers in particular, after I had already sketched a sizeable portion of the map and our group had started playing. This is why the rivers in the "Kendril" area, for example, make little sense.
Another part of the reason is basically magic. The slice out of "pac-man island"? Magic catastrophe millennia ago. That snowy/icy biome right next to a wooded area? Gigantic plateau that magically rises kilometers above the surrounding area.

I'd actually like to ask for tips on that particular area. The whole landmass of the plateau floats above a giant hole in the ground, as explained in this expert rendition of the scenario:
Click image for larger version.  Name: Plateau explanation.png  Views: 38  Size: 7.9 KB  ID: 111912
I'm not sure how to make a neat border between the plateau and the surrounding land. For now, I've just drawn some weird ditch in the elevation layer, but I'm not sure I'm satisfied with that.

I'm also still expanding the grass/forest layers, still figuring out what amount of greenery feels right.


So, obviously still a WIP, obviously still a beginner, but I really like mapping out the ideas I have in my head .