Ever notice how moving forward in your career comes down to networking? Could be because 80 percent of job openings are never publicly advertised, according to the Wall Street Journal.

Part of being a networking ninja is maintaining some level of regular contact with former colleagues and clients, so you're never in a position where it's been years since you've connected.

The rest is all about reaching out in an appropriate way. Let these tips show you how.

Reach Out on Social Media

Finally, a legit reason to spend time on Facebook and LinkedIn during work: Social media allows you to get your name in front of old and new connections in an unobtrusive way.

Keep an eye out for profile updates or posts from your connections — announcing a promotion, new company direction or a career milestone. Congratulate them on their achievement with something along the lines of, “So excited for you” or "Way to go!" At a loss for words? Just hit "like."

"Cheering on your contacts on social media lets them know you stand behind them,” says Dorie Clark, marketing strategy consultant and author of "Stand Out Networking.” You’re not asking them for anything in return and there's no expectation of a reply. They (and their own contacts) see your name, and that puts you on their radar.

Calendar Regular Check-Ins

For closer contacts, like a former mentor or client you've worked with many times, take the initiative by sending them an email or message, say, every 60 days or once per quarter, suggests Clark.

The note doesn’t have to be anything more than, "How’s it going?" or “I saw this article and thought of you” with a link to an industry publication. The goal is to casually check in.

Apps like Contactually or Refer.com make it even easier. Both track your contacts and prompt you to reach out based on time intervals you set. Refer.com even drafts the actual text of the message for you, based on the relationship level you have with that person.

Plan Small Get-Togethers

Arranging for a face-to-face with each contact is a impractical. Instead, set up small gatherings for a handful of people who all know each other, like your crew of former coworkers, for example, for lunch or happy-hour.

The get-together saves everyone time and energy. Plus, you avoid the discomfort of sitting across the table with one contact you haven't seen in a while...and no longer have much to talk about.

Show Your Gratitude

If one of your contacts taught you a valuable career lesson or helped you resolve a tricky issue, send a note of appreciation. Handwritten always comes off as more personal and meaningful. But an email or social media post can be fine.

There's no expiration date. "I think people appreciate follow-up and kudos whenever they come, even if it's months after the fact," says Clark. "You could write something like, 'Thanks so much to @joesmith for the great advice on blogging a few months ago. Here's my first post!' He will likely be thrilled."

If someone went above and beyond, say they helped you land a new job or client, consider sending an actual gift — such as a book on their favorite subject — recommends Derek Coburn, author of "Networking Is Not Working" and CEO of Cadre, a community for business leaders. Just don't wrap up something with your company logo on it. "That’s not a gift — it's a promotional item,” says Coburn. "Give them something small that they can use."

Share Your Talent

Offering a business-related favor — for example, arranging an email introduction with an industry leader, or posting a contact’s latest podcast — conveys generosity. "Most people tend to wait to network until they need something rather than reaching out authentically and genuinely," says Coburn. "Instead, take the initiative and offer to help."

Get the ball rolling by asking, "Tell me, who is your ideal client? I may know some people you should meet," suggests Coburn. Or, "What kind of investors are you looking to get on board? I'd like more clarity in case I come across an opportunity for you." You'll have a rep as someone who is positive and wants others to thrive.

Always Update Your Contacts List

People get promoted, marry, move away and switch specialties. Keep up with all the shifts by creating a Google doc or spreadsheet that lists all your contacts by name and includes what they do and how you met — and update it every time something changes, says Clark.

Make sure any page or site that lists your professional details — your job title, company name and contact information — is also current, so people can easily reach you and get an accurate sense of what you have done and currently do, says Clark.

Give Them Space

Staying close to business contacts means knowing when to back off. "If a colleague is really overwhelmed, it’s a nice gesture to periodically send them an email or leave a voice message and add, 'No need to respond,'" says Clark. "This shows a lot of respect for their schedule, because they may be too busy to get back to you and likely feel guilty about it."

What if you've reached out several times and continue to hear crickets? Only follow up again if you have a good reason. "People are busy, so it would be foolish to write someone off if you didn't hear back from them once or twice," says Clark. "They could be traveling or having personal issues that make it difficult to respond.”

There's a chance you have been dumped from their network. “If they ignore three messages sent over a span of time, especially if you have particular questions in your notes, then you can assume they don't want to keep up with you," adds Clark. Just move on.