Mostly just relax, enjoy this time, and enjoy the people around you! Drink lots of water, do activities that you enjoy and which calm you, and trust your vendors and the plans you've already made. Congratulations!!
For yourself, minimize alcohol and/or high salt/fat foods (if you consume them), and try to start drinking a bit more water each day.
If you're a bit of worrier like me, maybe review the day-of timeline, check the seating chart one more time, figure out which vendors you should do a week-out confirmation with (for the date, and time they are going to arrive, and who they look for when they get there, as it probably won't be you).
Try to spend every few nights just relaxing, take some bubble baths, read a book... Make sure your skin care routine is in full swing, maybe even avoid face make-up when you can over the next week or so...
Most of all, just get excited! It's almost here!!!