To replicate the Soviet use of scorched earth our group has the following house rule. During the non-combat phase a player may cause maximum damage to any Industrial Complex, Air Base and Naval Base in a territory he owns. This makes any conquering player having to clean up the mess.
Recently I was watching a video of this game being played on a custom map where all the air bases and ports were printed on the map. That really made set-up much easier and improved map clutter. To create the same effect we glued the small Industrial Complexes, air bases and ports symbols to the maps and the excess pieces are placed when purchased. It works terrific!