Just returned from a trade show and I have some observations:
1) Suits look a lot better than logo short sleeve shirts. Let's face it, very few people look good in those shirts. Sure you might think it's cute that everyone has matching shirts but unless everyone spends a lot of time in the gym....... And make sure you polish your shoes.
2) If you carry multiple products, group them. That way you can tell interest by where someone is standing.
3) Movement and color catches the attention. Have BIG monitors showing continuous motion. Every 4th or 5th slide, put up a point. Make sure you have 4 sets of slides in rotation.
4) Keep it clean, keep it simple. It's better to have fewer things and flow.
5) Stand back and watch. Go about 30 feet away from your booth and watch. See where people tend to go. See how the staff interacts. If the staff gets clumpy, break it up. If you have chairs and tables and the staff spend their time sitting in them, get rid of them.
And finally, you don't always have to be selling. Trade specific small talk is great.