If you do want to take control of the first social media image, try and get it done as soon as possible. Bear in mind that you won't really be thinking about Instagram or Twitter as you sign the register and, if you're sensible, you will have left your phone in your hotel room or with a relative to keep it safe so you won't really be in a position to fire up a "Just Married" selfie before you walk down the aisle. And be understanding if a guest just gets carried away and goes straight to Facebook as they do with all the photos they take.