Should 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 as part of your living room; this is like a miniature version of Disney's Epcot. You might incorporate Asian tropic samurai, dragons and plants swords that would incorporate all three themes. The thing is, regardless of the themes, there may be common ground found.