As I discussed a long time ago, I developed some basic social skills relatively late (post-college) because I was painfully shy, spent most of my time ignored by those around me, and I had a crippling lack of self confidence. I knew I was supposed to "network" at technical meetings, but I had no idea how to do so.
I was going through old posts and this one on networking reminded me of a recent realization I had - I have a network! When I am at a technical or business meeting, I know people or have some familiarity with their office/company expertise, and we discuss the things that annoy us or that we need, and we end up solving each others' problems and exchanging business cards.
So how did I change from a clueless grad student to a networking maven? Well, I've been in the business long enough that I've met a lot of people. I know folks from grad school, from the conferences I've been to, and from the various consulting firms I've worked with in various capacities.
Here's my one piece of advice for effective networking for newbies: an effective network is based on mutual self interest. Don't worry so much about meeting with industry/academic bigwigs - they're not going to remember you or care unless you have something to offer them. Instead, talk to your peers. Try to find something in common with the other early-career attendees. If you're at a conference, look through the posters and listen to as many talks as you can. Do you have experience with a particular technique? Are you familiar with a particular department or regulatory agency? If you end up having a productive/interesting conversation (even if it's just venting about fieldwork or academic woes), then hand over your contact info when you leave.
Maybe you'll see that person you met (or someone from their department or company) at another conference. Eventually, you'll have a surprising number of connections that can pay off personally and professionally. For example, I just met a manager who was looking for some geologists who had experience with a specific type of drilling method. I happened to know a couple of geologists who had exactly that experience and could use the work. Did chatting with that manager help me directly? No, but I got to help out some folks I respect, and perhaps when I need something in the future, that manager will know someone...