My 6mm street track for chariot racing is finished and, I'd like to think, it's pretty nice. I intentionally went for a robust, blocky feel, with minimal detail. I want the attention to be on the racers, not on the streetscape.
The buildings started as cheap wooden blocks which were glued into assorted house shapes and them received a rough smothering of crack-filling wall putty. I always call it spakfilla, because that is the Australian brand I used to practically build/repair my first appartment, but it goes by many names and is easily found in hardware stores.
Everything got a priming cover of dark brown paint, followed by two top coats of textured off white to look like lime-washed mud-brick. I then used left over tiled roof segments from my 15mm ancient city (oo gauge Spanish roof tiles for train sets from memory) to add tiled roofing to my two shrines.
A quick set up of a hypothetical racing circuit, complete with short cut through the alleyway. I'm quite happy with that.
... and it all fits in a small tub!