1. Quality vs. quantity - The number of people you know does not matter. It is the quality of your contacts that does. Who are the decision makers? Influencers? Who can you help and how?
2. Slow down - Business relationships take time. Get to know people not only from a business perspective but from a personal perspective too.
3. Go low tech - In some cases, a quick phone call can be more efficient than many emails. Pick up the phone and even find time to meet face-to-face. Email is excellent when sending documents or directions - don't overuse it.
4. Seek diversity – Make sure you have a diverse network of connections.
5. Introductions rule! - When someone takes time out of their day to make the effort to introduce you, it is the ultimate flattery. This separates name droppers from the genuine networkers.

Source: http://mochamanual.com/mochamanual/Business-Building-Skills-101/