Now who said SnowSultan's Z-toon tutorial will not work with scenes?! All you have to do is set up your scene and when you're ready just import a simple prop, I usually use the Poser ball. Then parent everything in your scene to this ball - the easiest way by far to do it is using your Hierarchy menu, just drag and drop everything on the ball. Now when you select the ball got to the material window and set it to fully transparent, turning off highlights completely and setting highlight colour to black too. In your display/elements settings set the ball to cartoon shaded so you can see it to manipulate. Then just reduce the ball's z-scale and the whole scene will follow. Actually this is what I always do to manipulate scenes, not just for Z-tooning. It's useful for moving, scaling, rotating, etc entire scenes.