What's your conventional wisdom?

Mike over at Communicatio has some interesting "lessons learned" about working a conference. I particularly liked this one:

When you get to the meeting site, immediately find out the location of every restroom. Inevitably, you're going to be asked by an attendee, and you'll want to know the answer to that question. (Likewise, know the location and hours of the business center.)

I'd add: Bring along several changes of shoes, but don't take your shoes off until the day is over; and make sure everyone on staff knows who's in charge of what should an emergency situation arise.

What's your favorite piece of advice for those new to working an event?