Have you been messing around with GIMP's layers, opacity, and layer-masks yet? Those are probably the most important things to learn for drawing quick and easy shadows.
Basically finished the Gartshore Towers. I might still draw the base, but I kind of hate how podiums look on the diagram. I wonder what exactly the rules are when it comes to buildings connected by podium.
I'm actually getting pretty excited about drawing the delta. I have I bit of the outline done already, and I'm looking forward to drawing the armouries and its vines. I also have a bit of the Bell building drawn, so dibs!
You have any buildings you're currently tackling, Fazdeh?