Networking is a Process
Understand that networking is an ongoing process, not a discrete event. Succes comes from making new contacts, following up and keeping in touch.
Hardly a secret but it's easy to forget that relationships are built over time not overnight. The person you talk for 5 minutes at a networking event is not likely to refer you to her best client, even IF she truly understood what you do, even IF there were an opportunity, and even IF you were the best person for the job.
You need to connect at a deeper level and get to know one another over several interactions. Start helping each other in small ways, builging trust and respect as you go. And while you strengthen these reletionships, don't forget to continue to make new contacts through networking groups and events.
If you have a structure (active membership in one professional organisation) and a plan (meet 5 new people each month, call 2 existing contacts each week), you'll make continual progress rather than moving in fits and starts, which is much more inefficient and much less effective.