The first step of the Sandbox experiment turned into a much longer post than I had anticipated, and when I was done it was very late. I simply did not have time to do the last part of the first step, namely placing rivers and forests.
I did well by that decision; it took me two evenings to get it done. Now the world looks much less barren:

It probably still needs some additional rivers but this will do for a start. Some details for illustration purposes:


In the next step, I will finally get around to actually writing some background about this world. Stay tuned.
Continued in Part 2.