The thing I hear the most from brides is "wow my room is so busy!" and it's so true. The getting ready part of the day, despite being chilled, is the most chaotic busy time of the day. Not only will you be having hair and makeup done, there will be various people coming in and out of the room to visit you, food arriving, the wedding co-ordinator will pop in to chat to you about the ceremony, flowers or rings might arrive to your room, and various other bits will happen as the day progresses. This can be even busier if family and friends are decorating the ceremony room in the morning of the big day!
My advice would be to just go with the flow, if I'm your photographer I can not only take the photos but also help you manage the traffic, keep breathing and drinking water. Oh, and eat! Breath in all the moments of the morning, enjoy the hustle and bustle, and know that it goes so fast. Rest, hang out with your friends and leave the planning to the professionals...you've done your part and now it's your day to enjoy.
Basically; eat drink and be merry!