This excelent book has a procedural framework of generating interesting combat maps. Beware this is not meant for "improv", but rather during the preparation phase of a game, as it can take some time to follow the procedure and generate the outcome. The procedure generates "Zones" (that actually fit perfectly the concept of Zones in FATE RPG) in which the user makes sure that the area has something interesting going on (without overdoing it). It is setting agnostic and generic, as it mentions categories of complications and events, not specifically tied to fantasy or sci fi. It is a good reminder of generating interesting places to battle!
[5 of 5 Stars!]