Ceremonies
Whether it is a registry office, a free ceremony, or a church, this part is mostly about experience, good instinct, and already being in the right place before the moment happens.
Ideally you barely notice me during the ceremony. I speak with the officiants beforehand about what is fine and what is not, and then I move within that frame as calmly as possible.
I move as discreetly as possible while staying close enough so nothing important gets lost. Especially in difficult light I usually work without flash. It keeps the atmosphere calmer and usually leads to more believable images. And while you as a couple are usually focused on the front, I also catch the smaller moments behind you: reactions, glances, a smile from a guest, or exactly the scene you did not see yourselves.