When you see a room full of people, make sure you are not thinking like a mosquito, looking at them as something to suck dry, to get what you want and move on.
It's important to meet people, but more important to really get to know them. Ask questions. Listen. Make a point of discovering what you can do for them.
The best opportunities will come from real friends, not “contacts”. Be a good friend. Relax. Don't be a mosquito.