[Classical]

My tip to you is only pay attention to detail where it counts. For example, placing junk all over the ground doesn't really give an "apocalyptic" feel. Sure it can help with the realism but in the end it will simply create unnecessary lag for players and won't pose as anything special. You're going to want to give an eerie effect using large structures and collapsed buildings to demonstrate the extreme impact that this so-called "apocalypse" has had on the city. My suggestions would be to make sure everything compliments each other; which includes not having a bunch of random objects in unrelated areas (e.g. a bunch of crashed planes everywhere) - You want to allow the player to immerse themselves and create their own story; so perhaps have one area where a plane has crashed and a bunch of supplies or a camp next to it; which could pose the question, "Where there any survivors?"