Don't forget your pen, your business cards and your torch.

Business cards and pen seem fine...but a torch. You don't actually need a physical one but you do need a mental one.
You need it to put the focus on others. One key issue for people is they spend too much time focusing on themselves, hence their nerves when attending an event. When you give your attention to others, be more interested than interesting,and focus on others, you don't have time for nerves.