Thankee!
I have two schools of thought. Most of them depend on whether or not I've done any preparation. When I'm prepared I tend to make my battles like a strategy game, laying out a map with some chess pieces, a pocket tape measure (1cm = 1m sometimes 2m), and a view random tidbits for cover (bottle caps for tables, erasers for cars and trucks and lay out the battlefield precisely.
However, when I'm unprepared I lay out the battlefield randomly, say when the player says "I find some cover." I then just pick something at random and play from there. Players who don't ask questions about their surroundings are treated as "Oblivious" (because they are) and usually end up in hot water.
I prefer to be prepared but sometimes that just doesn't happen. Order is a secondary effect of proper planning, basically; as context is to improv.
