I often speak to people that are organising corporate presence at a technical event, they might ask me to speak or perhaps work on a stand. I have a few questions I always ask, but I will often ask what is the objective and key message for the event.
Quite often the response is "to do something cool", I understand what they mean, they would like our event presence to help with perception change, but it's telling when this is the only objective. "Being cool" isn't really a goal you can easily aim at.
The best events marketing people I have worked with here at Oracle and also at Microsoft were able to clearly and succinctly articulate what the purpose of the event was and what they hoped to achieve by attending.
If you don't define clear objectives, then you can't measure them.
If you can't measure then you can't learn, and
If you cant learn then you don't get better.
A clear objective is possibly the most important thing to work on when planning the presence at an event. It will guide what you talk about on the stand, how the stand is designed, what you give away, the content of your talks and the everything else.
If someone comes to the stand and says "Why are you here today" everyone involved in organising and delivering the event should be able to answer that question with a single sentence.
If you can't, you might want to ask: Should we be doing this event at all?