Sometimes a large border suits the image:
When dealing with family shots, they can be a little repetitive so it makes sense to make a pattern out of the repetition:
When considering double spreads, it's a good idea to have the left page relating to the right page.
It's fun to have a large 'lead' photo with smaller detail shots on the left
Finally, toning can bring out the mood in the photo: on the page below, the toned image has been placed to signify the end of the formal portrait session - the next page introduces the reception.