What the church allows comes first
Every church sets its own rules and they are not the same. Some ask the photographer to stay behind a line, some allow nobody past the chancel step, most do not want a flash during the vows. We ask the priest or the parish office in the week before rather than finding out halfway through the ceremony, and we work on fast lenses and available light so the answer is usually yes.
The order of service
Processional, the giving away, the vows and the rings, the signing of the register, the recessional. The signing is the one couples forget to ask for and the one every family later wants a copy of — it is the only moment of the ceremony where everyone involved is relaxed and looking at each other rather than forward.
A church ceremony is quieter than it looks in photographs. Much of it is people sitting still. The pictures come from the aisle, the faces in the front two pews, and the moment immediately after the recessional when it stops being formal.
Reception
Cake, first dance, speeches, and the long tail of people finding each other. We stay through it. The speeches in particular are worth having properly — they are the only part of the day where the family says out loud what it thinks of the couple.
