I always bring business cards and I make 100% effort to meet everyone at every table I sit at during the sessions. I speak to them.
I maximize my time with the sponsors. Even if they are not a sponsor I could partner with, you never know who knows whom.
I plan out my sessions before I get to the event and have a backup plan incase something falls through with the original session. I make sure to attend everything I have chosen.
At these events we hear and see a lot of great things that others are doing, or you should be doing. After each session, I make a list of items I want to implement when I get home. I also make a list of research items.