Heavy nuke scenes 1

Few words about heavy scene management.
Working on Going Postal I had the opportunity to work with very large scenes, especially the opening sequence.
The main experience: if possible, break up shots/scenes into smaller pieces! In this movie I wanted to see in some aspects the boundaries of 3d in nuke, so I decided to handle my quite complicated shot in one nuke scene. It involved a three matchmoved greenscreen shot, and a matte painted multiple projected full city establisher, connected with a quick moving cameras (and those motion's blended seamlessly) above a large scale terrain, with constantly changing lighting condition, from daylight to sunset, in a multiple piece 3d projected environment.
Ok, it sounds bad, and it was bad. The result... not so bad, but could have been better :) But it was a really great experience with nuke. Of course, it could have been done in 3d, but the 3d department was full of work, so I did it completely in nuke (not counting of course the mattepaints, and matchmoves)
I don't want to write a whole essay about it, so I just write my thought as quick tips, or guidelines.