I actually have 2 things that I feel strongly about..
1) I typically am acquaintances with many of my brides. So, they announce on every public forum they can that I will be shooting their wedding which is great publicity, yet immediately after the wedding they post the typical very blurry, underexposed, heads cut off wedding photographs shot by their friends and members of their family without stating that they aren't mine.. which could be very bad publicity!
Devil's advocate: I typically post on their public forum photo albums in a very polite manner.. "Oh, are these the photos your friends took? Your professional wedding images taken by me will be ready by xxxxx. I can't wait for you to see them!" It's my method of damage control until I figure out something better. I really do not know how effective it is.
2) Bride's family and friends constantly calling for me to take shots that THEY want. Since I typically shoot small weddings, which typically tend to be in very poorly lit, small churches, the family likes to flock toward open windows and doors for the shots because they think the light is better. This creates a unattractive backlit situation usually full of parked cars, and the necessity to re-adjust all of my settings repeatedly.
Devil's advocate: This is one main reason for my contract. I am there and being paid to make sure the Bride (and groom, but not as much) is happy. I address my "creativity aspect" well before the wedding and I ask for a list of specific shots important to the bride. She realizes I will do whatever she wants within reason but ultimately I shoot to my taste, which is why she hired me in the first place! My brides understand that they must have a person or two designated to interact with me after the ceremony and "direct" the formal family shots. That's where my responsibility ends as I do not know many of the guests, and I am not going to be ordered around by everyone there. Yes, I slightly attempt to pacify some guests, especially her parents, but all in all.. it's all about the bride.