For those who send out plenty of networking emails and phone calls only to hear nothing but silence, the question isn't why they should network, but how. A few things to consider.

By Deena Shanker

FORTUNE -- When Shira Saiger headed to Cartagena, Colombia for a friend's wedding in October 2010, she wasn't expecting the trip to lead her to her dream job. But as a corporate attorney at Gibson Dunn's New York City office, she was always looking for an opportunity to jump to the legal offices at a media company.

The bride's sister knew an attorney at ABC, and after following up a few months later, Saiger passed along her resume, not knowing what -- if anything -- would come of it. By July, she was a lawyer at Hearst.

Networking didn't always come easily to Saiger, who admits she was initially shy about reaching out to people she didn't know. "But once I got more in the habit of it," she says, "it got much easier to do."

A 2009 survey by Challenger, Gray & Christmas, an outplacement consultancy, found that Saiger's experience fits the rule, not the exception: The report ranked networking as the most effective way to find a new job, beating out social networking sites like LinkedIn (LNKD) and Internet job search engines like Indeed.com.

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Christine Shin, career counselor at Barnard College, says she tells her advisees that they should be putting 80% of their job search time into networking and only 20% into cranking out resumes. But for those who send out plenty of networking emails and phone calls only to hear nothing but silence, the question isn't why they should network, but how.

Like Saiger originally did, many people feel uncomfortable networking because they feel like they are asking for something -- a new job. But Shin suggests looking at networking in a different light: "Networking is making connections," not asking for a job.

For people who don't naturally find it easy to talk to strangers, networking can be difficult work -- far more stressful than blindly applying to jobs online, for example -- and when efforts seem to fail, many people give up. The first step may be to lower your expectations. According to Shin, for every 10 people a professional networker reaches out to, he or she may only hear back from a few. "They key is to emphasize the positive. If those two people got back to you, immediately follow up," she advises. "Go see them even if they're not working that closely in something you want." She adds, "Try not to obsess too much about the 'No's.'"

Asaf Katzir, co-founder of CareerSonar, a website that matches your LinkedIn and Facebook (FB) connections with the Internet's seemingly endless job listings, offers similar advice. "If the person [you've reached out to] doesn't feel like they can really help you, and they don't want to say it out loud, so they ignore you, try to find someone else to refer you to the job or move on to the next opportunity," he says. "There's surprisingly a lot out there."

Saiger's experience is evidence of the power of positive thinking and not taking those "No's" -- or, more likely, lack of responses -- too personally. During the nine months she spent networking, Saiger estimates that she reached out to at least 50 people, many of them people she had never met before, and didn't hear back from as many as half of them. "Some of those people were incredibly responsive. Some of them I never heard back from. Some of them I sent follow-up emails to and then they were responsive," she says. "Some of them introduced me to other people to network with. It was a wide range of responses."

Try to learn from whatever mistakes you make along the way and just keep plugging away at it. "Be respectfully persistent," Shin says, by sending a single follow-up email to a potential connection if you haven't heard back. "People are busy," and end up missing emails.

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While Shin recommends just the one follow-up, Gen-Y self-help guru Alexis Sclamberg, who relies on networking to meet editors, land speaking engagements, and find more media outlets to write for, takes a more assertive approach. "I send one email a week for at least a month before I give up on somebody," she says. "If I follow up two more times, the likelihood of my hearing back is very high."

Sclamberg also recommends networking with people where there may be a mutual benefit. Even when she was just starting out and had little to offer to colleagues, "I always just offered to support their work, even if I didn't have anything specific I could give them."

Keith Ferrazzi, author of networking guides Who's Got Your Back and Never Eat Alone, echoes that lesson, saying that networkers need to learn to "lead with generosity." Whether it's just by being warm and friendly, offering something in return (e.g. to reciprocate with a professional favor or even to volunteer your time to the person's favored charity), or making a personal connection. "Nobody really has time for anybody unless you give them a reason to have time."