Basically, it comes down to this.
Your big day! Your job is to show up, and enjoy the crap out of it. My job is to know who and what are important to you, and document it.
The best photos happen when you have no idea that you're being photographed. I promise you that real is more memorable and interesting than perfect when it comes to photography.
You can't plan memories, they appear in their own way in the little details in your pictures.