I've exhibited at Sands for another, much larger show. I'm not going to read the 80+ posts above to avoid duplicates, I'll just offer my advice:
1. Footwear - if someone is judging you by what you're wearing on your feet they have either never been to a trade show, or are pretentious d-bags with unrealistic expectations and have no business being at a trade show. Wear what is comfortable and matches the rest of your attire. You'll be standing for 8-9 hours, plus walking back and forth from your hotel. COMFORTABLE.
2. Attire - polos/golf shirts are business casual and perfectly acceptable in most circumstances. When I see people in suits at trade shows I feel bad for them. Unnecessary especially for the style of booth IPVM is. If you were wining and dining a CEO that is going to place a billion dollar order with your company, sure wear a suit. Having said that, pack ONE in case you get invited to an event that it might be prudent or required.
3. Water - yes. Have lots of it at your booth. You will be talking a lot in a dry environment and you WILL lose your voice. Cepacols for the latter.
4. Underlay - order the double thickness for your booth next time (if you haven't already). Your feet will thank you for it.
5. Chairs - mandatory. Sit when you have a break, but if anyone passes by that you want to engage or someone approaches your booth, GET UP OUT OF IT. Unless it's the last day and you're exhausted, in which case apologize/ask permission (not that you really need to) to stay seated. Attendees know what it's all about and will have a laugh with you while insisting you keep your seat.
6. Security - I would think that something like ISC would be the epitome of nothing walking away but according to some of the above, it still happens. Sad. Our show had about a thousand armed security patrolling so I just hid a few critical things behind the backdrop and took my laptop with me, never had a problem.
7. Freeman - some of them are great, others are typical lazy union slugs. I avoid them as much as I can and carry my own gear in/out (I drove to Vegas last time and brought everything with me). If you're shipping then you have no choice. If you have them take away crates/boxes at the show start, you could wait 5 minutes or 5 hours for them to show up at show's end. I got lucky this year. The guys next to me didn't.
8. Last-minute shipments - if you have something to send in last minute DO NOT send it to the venue or Freeman will get involved and bill you accordingly. Send it to your hotel.
9. Shipping out - don't forget about the Fedex center IN the Sands Expo. It is very useful for sending stuff out. It is usually pretty packed so plan your time accordingly. They also have a print station but if a printer goes down and there's a line-up of people doing shipping/receiving, they will NOT prioritize fixing the printer.