In case your chosen themes accommodate one another, you can create a unifying theme. Consider this: your spouse wants an Asian theme, your teenage daughter wants a gothic theme and you want a tropical theme. In such varied combination you may opt to do an around-the-world theme in your living room; this is like a miniature version of Disney's Epcot. You could potentially incorporate Asian tropic samurai, plants and dragons swords that would incorporate all three themes. The thing is, regardless of the themes, you can find common ground that can be found.