The half of the answer lies in the question itself. People happen to decorate their houses for the wedding day. The list they do – clean their house up. Some people may buy balloons. Watch for flowers as well. It is nice to decorate your video with those accents created for the wedding.
Check right up front. The house may be decorated from outside. It may be the entrance, the patio, just nice flower beds. Once I had to shoot a big heart made of the rose petals carefully laid down on the front lawn. It was pointed out in my contract; I was reminded to shoot that heart as soon as I walked in, but only blind person could have missed it. The shot of the petal heart turned to be a good opening for that segment of the Wedding Video.
Check as well for some small decorative details in the house: it may be other family members wedding photo (mom and dad? older sister?), a casual photo of a marrying couple stuck on the fridge. It may be an old clock, especially if it shows right time. You don’t need to spot and film all these element at once. It may look even better if you spread them through your video creating some rhythm.