Thanks for your input groovey.

Some answers for you:
  • No, I didn't take into account the latitude when placing mountains. Like you, I don't know if I should. You have a point when saying that deserts erode mountains (wind and sand), but I suspect other latitudes have other kinds of erosion (water, ice expanding). So does one kind of erosion go faster than the other? No idea.
  • I placed the old mountain ranges rather randomly where I thought it would be nice to have mountains. The only aspect I took into account was the distance between the coast and the continental shelf (for coastal mountains): if they were close together I gave the mountains a steep slope, if they were far apart I gave them a gentler slope.
  • Ah, the big lake! I had to have a really, really big lake - bigger than the Caspian Sea. The problem was where to put it. I figured that it could be placed where it was surrounded by high mountains and/or large plateaus with lots of rivers running off them (especially off the huge plateau to the lake's east). The lake would be in a depression with slightly higher land to its north and with an outlet to the ocean in the west. But, as always, my logic may be flawed...

Cheers - Akubra