Our boys each have their own room and neither is 'allowed' in the other bedroom unless invited so to speak. Moo has all his little cars, trains, Legos etc that aren't appropriate for Buster to get hold of (he eats anything!) in his room, Buster has all the babyish stuff and there are toys all over the house they can both play with.

I never thought I would be so strict but this is the only way we have any kind of harmony in the house at the moment. We recently realised they needed a space that was all theirs, with no one eating, throwing or knocking over precious items I'm sure it will change as they get older!