So what are your characters' favourite things? Why do they like these things? Is there any one thing they could not be without?
My magical Fairy Kingdom is quite happy to pinch ideas from other worlds that it likes and adapt them to its own use. So do your characters collect things from other worlds or stick strictly to their own planet/universe etc? Do your characters look down on the cultures of other worlds or seek to learn from them?
And for those characters allowed to explore other worlds, what do they make of these places? Do have have favourite places to visit?