Lets talk about jitters, nerves, anxiety, worries, fear, etc, you get it.
"I think it's healthy for a person to be nervous. It means you care - that you work hard and want to give a great performance. You just have to channel that nervous energy into the show." - Beyonce
In a nut shell that really sums it all up. When we are nervous, the only thing we can really do is address the nervousness, accept it to some degree and then channel the heck out of it.
No matter how well seasoned a photographer you are, I'm guessing some wedding day jitters will pop up. So let's talk about those tricks of the trade, to quell said jitters, that will help you get the most out of the big day.
The first and most important, is your "morning of" pep talk. I know, I know, it sounds cheesy, but taking 10 seconds to mentally tell yourself that you've got this, changes your whole perception of the day. It may be minute, or only last a minute, but it will have a calming effect.
The second thing that happens, is normally the morning of a wedding I have these moments, as I am getting ready, where I think I will totally flop on my creativity in every which way. I find myself pulling up my instagram and looking through old photos, or popping onto my Pinterest pages to spark any sort of imagination and confidence that I can do my job. I feel like to some degree it is my brain reminding me to get a refresher on what it is I do. Sure, most of it is second nature, but there is nothing to be ashamed about for looking back at old photos you have taken and reminding yourself of the poses that worked and that didn't. It's a mini refresher corse before the big day. You will thank yourself and more importantly, so will all of those who get their photo taken by you.
The third thing that causes me some anxiety is keeping track of the schedule and all of my equipment. Several ways in which to combat the nerves of staying on schedule are talking with your couple well before the wedding day about a timeline. Sit down with them and get every detail you can about their day. Sometimes, if they have a DJ, they will provide the couple with a breakdown of their cues and times which can be very useful to you, as the photographer, so that you are not caught off guard by a sudden speech or special game.
Create your own timeline with the couple from arrival to departure, covering everything from the getting ready, to the walk down the isle, to the grand entrance, and all the small, but extremely important events that happen throughout the reception. Once you have discussed all the possibilities with your engaged couple, write it up and screenshot it. We live in a day and age where we can have specialized wallpaper on our phones. Take the photo of the timeline and make it your lock screen image for the duration of the wedding day. Learn from my mistake. Thinking you will be able to access your email and pull up the copy you sent to the couple, may not always work. Especially when you are in the middle of a forest with very little cell range.
As far as where to keep your equipment, this is also something I highly advise you to bring up with your soon to be wed couple. If you are unfamiliar with the wedding venue that you will be photographing at, usually the couple will know of a place where you can safely store your camera bag when it is not in use. I also suggest, if you can, use a camera gear backpack to store everything. It is easier to have a backpack while running between locations when you don't have time to set it down. Also, if you are shooting with two cameras, getting a strap that you can easily hook and switch between, will greatly help out during the ceremony when you are bouncing between close up and far shots. You want to be comfortable with anything that you use so that you are confident while photographing their special day.