A large, diverse, and engaged professional network would help win your dream job. And being a part of a professional network means adding to it on a regular basis. Don’t wait until you need a favour or are desperate to send your résumé to a hiring manager. Valuable contacts are often on the perimeter of your social circle — they’re the parents of your children’s friends, they’re in your school’s alumni association, and they’re your friends’ friends.

So how do you turn these people from relative strangers into valuable network contacts?

Spot them

An effective professional network has a wide variety of people in it, including people from outside your industry. So how do you decide whether someone you meet at a cocktail party is the one you want in your circle? Well, don’t be too scientific about it. Simply liking someone is a very good reason to add him or her to your network.

Look for people who are active in and passionate about their field (whatever it is), and who seem interested in what you’re doing. Also, people who communicate well are likely to be “connectors” who have their own networks that you may be able to tap into.

Always be open to possibilities. That means being friendly and outgoing in your personal life. Go ahead — strike up a conversation on your next plane trip (but not at the beginning of a long flight — people are more relaxed and less fearful of getting “trapped” if you wait until the plane is close to its destination).

Check network

Don’t stop at cocktail parties and networking events. Also seek out new contacts: check your friends’ social networks for influential people in your industry, or for people who work at companies on your “dream job” list.

Now — and this is important — don’t be a spammer! There has to be a reason you’re asking for an introduction or introducing yourself. For example, “I’m a friend of your friend”; “I see we both attended the same university and are both in advertising”. Don’t make a connection for no reason.

Of course, the best time to make a connection is when you have something relevant to offer.

Offer value

Effective networking begins long before you need something from your network. Demonstrating that you have something to offer builds a foundation of goodwill. Every time you talk to someone in your professional network, you should ask what he or she is working on, so you’re always aware of the problems your contacts are trying to solve.

Now that you’ve got your list of desired contacts in mind, the next time you read a great article, attend an industry conference, or know of a job at your company, think of not only the people in your network but also the people on your desired-contacts list. Ask yourself, “Who would benefit from this knowledge?” Then share your knowledge with those people.

Go out of your way to introduce people who you think would benefit from knowing each other.

Another great way to get connected is less aggressive but lays a very effective foundation: simply become an enthusiastic audience member. Follow desired-contacts’ blogs, and comment (thoughtfully and professionally). Retweet their tweets —people pay attention to that. Share their announcements with your networks. And so on.

Of course, there’s a fine line between “fan” and “stalker” — just keep in mind that if it’s creepy in real life, it’s creepy in the digital realm, too.

Stay in touch

Your efforts to meet new contacts are wasted if you let relationships lapse. An effective networker is participatory and involved.

Sounds like a lot of work? It doesn’t have to be — in fact, your networking efforts shouldn’t take a lot of time.