When it comes to weddings, the most important phrases you can use are "Yes, Dear" and "I love it." 

Also, never ask how much something costs - at least not in front of your bride-to-be.  That suggests you're ranking money more important than your relationship and your future happiness...as if the choice of what kind of appetizers you serve at the reception can determine whether you will want to wake up next to this person every day for the rest of your life!