Working on transfering some of my concept art into 3d stages for a unity game, trying to figure out how to make 3d backgrounds in maya that are played on a 2d stage like blazblue and Persona 4 arena

http://images.wikia.com/megamitensei/images/2/2e/STAGE1.jpg

http://shoryuken.com/wp-content/uploads/2011/12/Persona-4-The-Ultimate-In-Mayonaka-Arena_2011_12-08-11_047.jpg

any ideas?

Someone may have a wiser answer but it's mostly just about what looks good and keeping the triangle count to something reasonable. There are also some nice videos out there, for example this one from the creators of Trine 2:

Search their channel for more.