Change the program, timings, way that food and drink are served. An absence of a scalable creative framework encourages incremental innovation in lieu of disruptive innovation. For a low-cost and easy idea, you can aim to put extra tidbits of information about the attendee on their name tag. For trade shows or exhibition, the cardboard booth is becoming popular.
How Place + Technology + People Can Help Solve 21st Century Problems
How fun is this 3D photo booth?!! Nobody cares about billboards.