While this list is not all-inclusive, it can serve to bring you up to a quick speed on some minimum requirements for operating a booth at a trade show.

1) It is of utmost importance that the staff be friendly, knowledgeable and courteous.  They should be good communicators who can completely describe the product or services you offer.

2) Don't have chairs in your booth, unless they are used to conduct business with clients.  Booth workers should never sit. They should stand in order to make immediate eye contact with the show attendees. Booth workers should greet or
at least acknowledge every single visitor to their booth.

3) The Front of the booth should be open inviting show attendees into "your space".  Don't "hide" behind a table or other booth prop. 

4)Don't schedule booth workers for long shifts if all possible. Two-hour shifts are great...especially at a busy show.  If this isn't possible, at least schedule frequent breaks throughout the day so booth workers can either sit and rest their legs, take a walk around the show, etc.

Also, if a booth worker must be there for the entire day, encourage them to change shoes a couple of times. This makes a big difference.

5) Take the time to be original in your promotional items. Try to do/have the "unexpected" at your booth to attract attention. Your promotional item should be something of value to the visitors to your booth...or something so unique that they have to stop and ask about it.  When possible, use quality products linked to your type of business with complete imprint of your name, phone, website, etc.