The wedding day can be overwhelming and tiring. Some of the brides I have worked with wakes up as early as 4AM in the morning to do makeup and hair and they are often at the dinner reception dancing until 1AM - 2AM in the morning. With all the little things they have to watch for and make sure run smoothly, the wedding day can be pretty long sometimes.
I always recommend brides to bring flats for walking during the formals so their feet will not get sore and have lunches prepared in advance so the wedding party does not forget to eat until they are ready to pass out. Comfortable shoes are also recommended for the reception for dancing. Often brides will take off their veil for the reception so it is easier for them to move around without worrying the veil to be pulled or stepped on by accident.
For clients who book a shorter day coverage with wedding photography or videography, it is often a good idea to schedule your first dance right after the grand entrance to ensure it is being photographed and all guest can see it in case some older guests wants to leave early.