I won't just give you one, I'll give you three!
1. Make sure you eat! - it's a hell of a long day & you're going to be on your feet and running around all day, and most couple don't usually eat until 6:30/7pm, and even by this point its broken up talking to guests and speeches. Make sure you have plenty to eat in the morning whilst getting ready. We want to see you smiling throughout the day and not feeling hangry.
2. Make sure hubby-to-be allows space for you at the altar. I see alot of grooms stood in the middle and then when their bride arrives down the aisle they're both off center. & I'm pretty good at photoshop but I can't fix that in editing!
3. Don't sweat the small stuff. Your day is going to be amazing regardless of your place settings, so try to relax and really enjoy the moments before you're married because it really does go so fast and before you know it the day will be over! - No matter what happens you'll both have eachother and your beautiful love and that's the thing to cherish!