Number RSVP cardS and log who has which number on a spreadsheet. Easiest way to track who still owes you an RSVP. When you don't get them back (and there will be many that you won't, its just how it goes) you know exactly who to confirm with.
It's a invisible ink pen, write the guests name on the RSVP card before you send it out. If it comes back without a name on it, you will know who it is from. This will save me A LOT of headaches. Interesting Or just number the RSVP cards!
Something fun for guests to do at the table. What should we name our kids? What is the most romantic place we should visit? What is the best marriage advice you have ever received? What is your favorite memory of us? Where do you see us in 25 years?