Everyone says the best way to find a new job is through your network; but it can feel like building your network is your second career. Take networking as seriously as you take your career, and don't make these mistakes that will undo all your efforts:
You don't network until you need something.
Sure, your network can help you find a new job. That doesn't mean you should wait until you need a new job to work on it. If you only reach out to people when you need something, they're less likely to want to help you. You need to be able to give something to the people you network with, not just take.
You only network online.
There's no question that online networking is easy. The problem is, because it's so easy, people don't take it seriously. Of your thousands of Facebook friends, how many could you actually turn to if you needed help? Probably just a handful that you know and interact with in real life. The same applies to professional networking; you can build deeper connections with people you meet in real life. Go to professional meetings and make the effort to introduce yourself to a few people.
You aren't specific.
If you're going to make a request of a network contact, be specific about what help you want from them. If you leave it to them to figure out what you want to do, they won't know what they can do to help. Be precise about your qualifications and the kind of career opportunity you're looking for.
You don't follow up.
Making initial contact is just that, making initial contact. To build a deeper relationship with a connection, you need to connect more than once. Don't depend on the other person to do all the work. Reach out with updates occasionally, but don't overload them with too many messages.
You don't say Thank You.
When someone in your network goes out of their way to help you, thank them for it. Let them know you appreciate their efforts on your behalf. A quick email is all it takes to make someone feel good about helping you and keep them willing to help you again in the future.