While this article is short it is informative. I have found myself at design events or meetings where all i did was sit silently and take notes or just listen to people talk, sometimes doze off daydreaming. It is important to have personal skills, charisma, an outgoing charm if you will.
It also doesn't hurt to show off your knowledge about your field, the event you are at, or maybe what you do. If you are at a design event, chances are you know more than one person or are not there completely alone, unless you are just super bold or the event was so badass that you just had to go.
I think talking to new people can be scary to everyone. I like to look for people that are not following dress code exactly. While I try to most of the time, it is nice to see someone wearing something more casual or unusual at events, to me that means they are outgoing, easy going, or just generally don't care ha. But it is nice to see people like that because it makes me realize all people, even professional designers, are just human and people like us. I'm sure they love imparting wisdom to younger designers too.