The key to a successful exhibition is planning ahead and planning for every eventuality.
Tip 1./ Stand Design
Depending on the stand design it is a good idea to construct the stand and artwork at the office premises before you leave for the event if this is the first time. This will highlight the complexity of the stand, how long it takes to set up and and how many people you need to help in the setup. It will also give confidence to the people setting up the stand to know all the tips and tricks and which bits to place first and what cannot stand without which bits. This will save ample time on the setup day.
Tip 2./ Extras
If the stand requires lighting or electricity check this is being supplied and if you need to purchase or request additional supply. It is doubtful that this can be requested on the day or setup day. If your stand requires electricity for a TV or laptop and this is not available it will not look professional.
Tip 3./ Promotional Items
Make sure you have enough promotional items and any free giveaways for the days you are exhibiting. There is nothing worse than saying "free XYZ with any sign up today" and then have to explain that you've run out. Also check with the promotors if there is anything that you cannot give away for health and safety reasons. Those pin badges might be harmless to most, but it certainly worth checking first.
Tip 4./ Stand out with your stand
You need to attract visitors to your stand with promotional products, great layout and presentation. Think about getting the maximum capacity of visitors to your stand without overcrowding. You need a stand (branded of course) where people can fill out details without having to find something to lean on. If possible consider a few seats for people to rest and where you will be able to chat and promote without someone feeling over-tired.
Tip 5./ Check Floor Space
Do not be tempted to go over your floor space 'a little bit' - it will be noticed and pointed out
Tip 6./ It's not a Party
Do not have any promotional music that loud that you cannot hear your visitors and potential leads. If people have to shout they stand a chance of walking away to somewhere quieter
Tip 7./ Have fun
Most importantly - have fun. If people on a stand are having fun and smiling and look approachable this will encourage people. Don't site down and read a book, expecting people to come to you.