the best way to start networking is to show genuine interest in what other people are doing. Don't start off by telling people about you and your business - ask them about theirs...

"what is their ideal customer/contact profile?"

"how would I know that someone in my network could be of value to you?"

"is there anything I can help you with?"

All these will normally get an open, positive response that will invariably give you great insight into the othe person, and lay the basis for a good contact.