Crispy has the good advice - stay hydrated. Drink water often. There are usually the big coolers of water around, so use them. The B vitamins in a drink like Propel before bed gets you more water and the vitamins and minerals to help your body recover before you get up and do it all over the next day. One must be aware that it will not fix a day and night of stupidity!
Take time to eat right, don't get so caught up that you forget to have a good meal.
Pace your self. It can be a long conference, so be there at the finish.