The word 'networking' is often misapplied and misused. Professional networking is not so much different from its social counterpart, where you are in casual interactions with folks working specific industries.
First you need to work on yourself:
Be informed about the basics of the sector. Do your research if it is someting that you are looking to break into.
DON'T exclusively focus on the work, try to get to know the person, their interests etc.
Second,
Make sure you exchange business cards.
Keep in touch with that person, whether its a quick email or an occasional lunch.
Third,
bring value to the relationship: this means that you need to contribute to interactions, bring you contact list, knowledge and resources for the other person. Remember, this is should be a synergistic relationship.
Acknowledge and appreciate the support. Make sure that you put that person front and center (in a positive light) if you get that coveted interview or position.
In my experience, South Asians and MBA students are the worst networkers. Desis come across too focused on "whats in it for me," which is not only boorish but also yields low results. While B-Schoolers tendto be desparate particularly when it comes to hard to break into industries. I mean I get it, you're going to be graduating May and need a job, what can you bring to the table? I mean I had people PM on this message board once they found out I was in I-Banking. Am I supposed to suddenly say "gee, your Pakistani and I should be honored that you're asking me for a job over PM?" Not going to happen.
I have a pretty strong social network because I don't come out with some mercenary agenda when talking with people: I genuinely like to interact with people and learn more about what they are doing in their careers. Let me illustrate: When I am not traveling and have a bit of time off, I like to race cars and belong to a BMW association. In that group there are 2 CEOs, 1 MD at a rival Bank that I am friends with. I became friends with them after doing an autocross series and we just don't talk about cars, but also work and how their families are doing. Last month, one of the CEO's son is applying to my college, so I met up with him to discussthe interview process and talk about the school. A year ago, that CEO had hired my bank for acquisition and I was the lead on thedeal team. So our support works both ways, professionally, yet I also know their personal goals, families anddriving habits. I would rather keep my network tight instead of throwing out business cards by the dozens.
So the bottom line is that you need to step up and be more social, do your research, and enjoy the process!