Many professional fantasy city maps depict little buildings (in either bird's eye or isometric view). In some cases these actually represent specific buildings, but more often it just seems to be filler and a few unique buildings are called out with distinctive color/architecture.

For example, I've seen John Edwards on the Cartographer's Guild do this....by hand I think?....and you can see a good example of this from this Warhammer map of Praag: http://vignette3.wikia.nocookie.net/...20130829165723

How do mapmakers do this?

Are they painstakingly doing this by hand? Using some kind of a custom brush in Photoshop? Some sort of algorithm or plug-in for Illustrator I'm unaware of?

I would love to incorporate this into my current mapping project, but so far I haven't found the answer anywhere. Hopefully one of you savvy cartographers can fill me in on the secret