You can mount
some partitions on the little ridge along the walls, like this:
It's the same basic principle as the old 'troupe stage above a window' glitch. That's the closest you'll get them to the wall, problem is of course that they end up 'floating', I use those little half partition things to cover that up as they sit pretty close to the wall by default.
Anyway, this 100% works with bookshelf's, it 100%
does not work with verdant partitions, I don't really know on the rest unfortunately. Will check later when I'm at home.