Be Interested, Not Interesting
Networking events can be tough for introverts, because most of us are not natural salespeople, and we think that networking is all about selling yourself. But that's not true. Networking is about building relationships, not "making the sale." A critical part of building any relationship is showing sincere interest in the other party. This is where introverts excel.
If you are a naturally observant and thoughtful person, you are likely an excellent listener. Put those skills to use. When you strike up a conversation, don't attempt to launch into an awkward pitch for your business idea or job skills. Ask the person why they came to the event. And instead of flipping it immediately back to yourself, dig deeper. Ask how they got into their line of work and what they like about it (or don't like). If you feel comfortable, ask about their families or personal lives. This will make an impression.
Once you have formed an actual relationship with a networking contact, it will be much easier for you to talk about yourself and your ideas. They will be interested in you because you were interested in them [source:Zack].