A collection of Indus environment thumbs sketches. These are all small illos from a 5 1/2" x 8" sketchbook that is dedicated solely to Indus environment roughs. Industrial locations and dark scary places.
Yes, doing these as smaller thumb illos (they're roughly anywhere from 2 inches to almost 4 depending) makes it easy to just plot out dense structure and details quickly. It makes doing larger production backgrounds all the easier when they're roughed out like this before hand.
Good observation and thanks for posting