Most people know to keep the important parts of their LinkedIn profiles up to date: a clear summary of their career and objectives, a list of the job they've held and key accomplishments at each one, any certifications or credentials to show off their skills, and of course, a photo of their best professional self.

But senior recruiter Kathleen Nolan says one LinkedIn feature is frequently overlooked and "underutilized," even though it can help your profile stand out: the recommendations section.

LinkedIn recommendations are essentially "little testimonials to what it's like to work with you and what it's like to be on a team with you," Nolan tells CNBC Make It. "I don't see too many people having that filled out on their LinkedIn, and I do think it can go a long way."

These recommendations can be from colleagues or even friends if you've worked on any big personal projects together, Nolan says.

Recruiters looking at your page may consider it a bonus if the recommender has a well-built-out LinkedIn profile themselves, worked for a well-known company or are in a management position, Gorick Ng, Harvard career advisor and author of "The Unspoken Rules," previously told Make It. 

"The higher up you go, the sexier the job title or the more credible the job title," he said.

How to ask for a LinkedIn recommendation

When reaching out for a recommendation, make it known you're building out your LinkedIn presence and what your goals are (for example, if you're trying to find a job in X field).

Let them know why you thought of them and specifically what insights you hope they can provide. For example, you might pinpoint that they were your direct manager on a project that had Y impact, and they had a chance to see you do A, B and C.

You can fill in those blanks with technical and soft skills that are important to the job you're looking for, like exceeding expectations or having a firm grasp of data analytics.

Finally, let them know the recommendation can be as short as one or two sentences, and there's no pressure if they don't have time.

Focus on up to three really strong recommendations, Ng said: "It's quality over quantity."

'It's not just about what you can do; it's about who you are'

These personal testaments to who you are as a colleague can be a good way to show off soft skills that might not show up elsewhere on your profile, resume or cover letter.

Recruiters want to hire people who can show they're adaptable, communicative, can solve problems, have emotional intelligence and work well on a team, Nolan says.

"It's not just about what you can do; it's about who you are," she adds. "You don't have to be best friends with everybody you work with, but certainly having a warm and professional working relationship is going to be key to getting good work done."

Leveraging every aspect of your network is crucial to break through in what Nolan acknowledges is not a normal job market. Hiring is down and workers are worried about mass layoffs and a potential recession.

"A referral is always going to be your best way in. If you have a friend who works with a company, if you know a hiring manager, if you know anyone who can provide some sort of warm introduction, it is a pretty sure fire way of getting at least least a toe in the door, if not your entire foot."

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