Wow, I put Fogdown in my 'Creation and depiction' tutorial as an example of great city building....so wonderful if you're going to improve it even further.

Your base is the kind of base that I use for the lazyman's city, but check this thread out.

Alfar has kindly made a 'context free' program which will make some interesting shaped buildings to break up the monotony of the voronoi / mosaic shapes, which I think will work excellently at this scale.

Please post lots of WIPs Redstar. My mapmaking is on hiatus while I'm waiting for a new computer to arrive (Thursday...hurrah!) and I'll be making a city quite closely aligned to the same principles you're using for Fogdown redux. I made a start here until my computer packed in...so I'd love to compare notes as I/we progress in our work.

All the best

Ravs