Blair Decembrele, LinkedIn's career expert, tells CNBC Make It that it's important for young people to know that your connections "are your most valuable asset as a professional." She says that if you're a recent college graduate who has just completed an internship or is about to start one, it's crucial that you focus on building and maintaining relationships during and after your time at a company.

According to LinkedIn data, 70% of professionals get hired at companies where they have a personal connection. Yet 51% of millennials feel uncomfortable about reaching out to their connections for a referral, and 40% say they avoid this step altogether during their job search.

Regardless of whether you're a recent college graduate or a more experienced millennial professional, nothing will benefit your job search more than maximizing the relationships you've already built.

"If you think that at the end of that internship there may be a job opportunity for you later on, then it's great to stay in touch and be transparent about that," she says. "It's also incredibly important to ask for feedback after that internship so that you can gain that professional experience and also know the things you really crushed.

She adds that if there is a contact you haven't been in touch with in a while, then there are multiple ways to rebuild that connection so that you don't feel awkward about asking for a referral in the future.

"First, connect with that person on LinkedIn if you haven't done so already," she says. "Tell them, 'Hey, I'm graduating and I'm starting to look for a role and I would love to get your advice on my career search. Would you be willing to talk to me for 10 minutes?'"

Doing this, she says, helps you to rebuild that relationship without asking for a job or a referral up front.

"Plan to go into that meeting looking for two or three strong pieces of advice or leads for you to continue your job search after that conversation," she adds. "This is a great way to stay top of mind without being presumptuous."

Bestselling management author and CNBC contributor Suzy Welch agrees that relationships are a key component to your professional success. But, rather than following the common advice of "get out there and network," she says you should "focus your energy on forging authentic business relationships" that go beyond a random business card.

"Human beings help friends," she says, "not 'contacts.'"

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