In my case I laid it all out perfect using a visual tool called Spriter.  Then I exported chunks of that scene to png files.  Now I am placing those files in world coordinates so they make up the bigger scene.  Not to mentions creation of physics images etc to go with it.  This placement is the “fun” part.  You need to get the hang of how many pixels is something off from the perfect location.

It’s a job I’d rather not do, but it is rewarding to finally be able to walk around the set I am building up.  Seeing the pieces slowing move into place, after try, after try, is kinda cool.  This is yet another thing that should make you ask yourself, do I really want this to be my job?  lol  You gotta love it.