About to celebrate marriages are - they should be fun. The more fun you have as the photographer most relaxed people you photograph will be. Perhaps the best way to loosen people up is to smile as a photographer (WARNING: I always come home from photographing weddings with jaws and cheeks hurt because of my strategy to smile.
One more piece of advice someone gave me the day of my own marriage. "Things go wrong - but they may be the best parts of the day." In every wedding I've participated in something tends to go wrong with the day. The best man can not find the ring, the rain falls as the ceremony ends, the groom forgets to do up his fly, the flower girl decides to sit in the middle of the aisle or the bride can not remember her vows.
These moments can feel a little panicked at the time - but it is these moments that can really make a day and give the bride and groom memories. Trying to capture them and you might find yourself with some fun images that sum up the day really well.
I still remember the first wedding I photographed where the bride and grooms car crash on a tram on the road to the park where we were going to take pictures. The bride was in tears, stressed the groom - but then we'd all calmed people began to see the funny side of the moment and we even took a couple of shots before driving onto the park. They were among the favorites of all.