Bad news: Your employees may not be that into you (or your company). According to a 2015 Gallup poll, only 32 percent of employees are engaged at work, meaning they feel passionate about their jobs, are committed to the organization, and put effort into their work.

It probably goes without saying, but employees’ engagement levels directly impact a company’s customers and bottom line. Companies with the highest employee engagement have 10 percent higher customer ratings. Furthermore, “companies with highly engaged workforces outperform their peers by $147 in earnings per share,” according to Gallup’s research.

If your employees aren’t highly engaged, it’s worth assessing how well you recognize them for their efforts. According to an HR Solutions International study, recognition is the key driver for employee engagement. Moreover, between 67 to 90 percent of companies report an increase in engagement after adopting an employee recognition program.

If you have an employee recognition program, you’re not alone; 88 percent of companies have one. But those programs are not all created equally. Read on to learn what research says about some of the most common ways to recognize employees.

Try these employee recognition strategies

1. Celebrate years of service

   The majority of companies recognize employees based on how long they’ve stuck around, but research conducted by Bersin and Associates suggests tenure-based recognition doesn’t actually make employees feel valued. That’s probably because most employers celebrate employees at distant intervals, such as every five years. Consider recognizing employees several times on mini-milestones (every 90 days, for example) during the first year, and then annually on their work anniversaries.

2. Base recognition on a company’s values

   A customized program that ties recognition to a company’s specific values is more effective than a one-size-fits-all approach, according to a Globoforce study. Ninety percent of managers with recognition programs based on values said it positively impacted employee engagement, versus 67 percent with non-values-based programs. Zappos, Buffer, and Motley Fool have all adopted value-based recognition programs.

3. Gamify

   It’s a hot trend to use the principles of gaming—digital badges, medals, or awards on leaderboards—to reward employees for certain accomplishments. The jury’s still out on whether gamification makes employees feel valued. Game-like recognition programs seem to be having positive results at companies such as Target and Ford Motor Company. However, a Globoforce survey of 706 full-time employees found 70 percent of participants did not favor a gamified recognition program.

4. Celebrate birthdays

   There’s little research on whether celebrating birthdays at work makes employees feel valued. However, according to an article by Dana Wilkie of the Society for Human Resource Management, there are wrong ways to celebrate birthdays. Employees have sued companies for age and religious discrimination because of the way birthdays have been handled in the workplace. Wilkie advises employers to ask first, and avoid emphasizing the age of the employee. Furthermore, as with any gifts, it’s probably more meaningful to give something personalized and desired over a token gift. (Safe bet: a paid day off.)

5. Promote health and wellness

   Research suggests wellness programs can successfully improve employee health and boost engagement and productivity, especially when employees have access to benefits such as stretching breaks, fitness classes, walking trails, and healthy cafeteria meals. So it makes sense that some companies choose to merge traditional recognition and wellness programs. Some also use gamification to encourage workers to meet fitness or nutrition goals.

6. Allow for flexible scheduling

   According to a study published in the American Sociological Review, when employees control their own schedules, their stress levels decrease. And employees’ stress levels are strongly linked to how engaged and productive they are at work. So it’s not surprising that research conducted by Boston College’s Center for Work and Family suggests telecommuting, flextime, and other non-traditional scheduling solutions tend to be advantageous for both employers and employees.

Sincerity is always best

The bottom line? Employees want genuine efforts that make them feel seen and appreciated for their strengths and efforts. If recognition feels fake, impersonal, or phoned in, it will probably backfire and make employees feel less engaged. The most authentic recognition usually happens in real time. Get to know your employees individually. When someone does a good job, notice it, mention it, and reward the employee with more projects they’ll love and excel at. Positive, honest, day-to-day interactions go a long way to create a culture of recognition.