With the holidays around the corner, planning leave time is at the top of mind for many employers and workers. Still, many employees lose out on vacation time every year. And that’s not good–studies show that when leave time is not taken, morale, health, and productivity suffer.

The tech industry, known for generous perks, has recently made big advances in offering substantial leave time for new parents. Mark Zuckerberg himself recently announced that he would take two months off after he became a father–and taking paternal leave is critically important. But even generous leave policies don’t guarantee that employees will take what’s offered, and the US is still one of the worst countries in terms of leave policies.

So how can we ensure that leave is really taken? TechRepublic caught up with Anne-Marie Slaughter, author of Unfinished Business: Men, Women, Work, Family, and Anna Steffeney, founder of LeaveLogic, for advice on how to ensure that leave time is used.

1. Remember how critical leave time really is

Employers need to “look at all the data about what burnout and stress does to health costs and worker performance,” said Slaughter. “They should also think about the cost of continually losing employees who cannot fit their work lives and their family lives together.” What matters most, she said, is the “quality, quantity, and timeliness of the work produced,” rather than simply the number of hours spent working.

2. Ask how many others have taken the leave policy

Slaughter advises all young women and men, when interviewing for jobs, to ask specific questions about an employer’s family-friendly policies–immediately. She tells them to ask “how many people in the company have actually taken advantage of those policies and still gotten promoted to leadership positions? Unless a company can answer that question satisfactorily, they will remain paper policies–open only to people who don’t plan to advance.”

3. Set an example

For these policies to work, those at the top need to lead by example by taking advantage of them–“in corporate speak, walk the talk,” said Slaughter. Steffeney is “thrilled” by Zuckerberg’s announcement, saying he is setting a “great example for millennial men to feel empowered to take their paternity leave. The faster we can understand that this is not just a women’s issue, the faster we can normalize the entire event in the workplace.”

Slaughter agrees “Zuckerberg’s decision, and the publicity around it, is exactly what we need to promote culture change among men–advancing the idea that caregiving is not only just as much the obligation of the father as it is of the mother, but that, in fact, men who do it are cool.”

4. Create a culture where leave is encouraged, not frowned upon

Just because generous, or even unlimited, leave is offered, it doesn’t mean that employees are encouraged to take it. Many believe that taking it will be seen as a sign of weakness–that they’re not working hard enough. When Steffeney attended the White House Summit on Working Families last year, she heard “a lot of discussion about women having to win the ‘boss lottery’ to truly have a supportive leave.” Her company, LeaveLogic was founded to help employers and employees to successfully manage leave time and re-entry into work.

5. Build in mandatory leave time

Unlimited leave policies are still relatively new and untested, and there’s a lot of anecdotal evidence that they may not be effective. Steffeney is “skeptical of a company’s motives to offer unlimited vacation without clearly defining the reasons and measurements of success for such a program.” And when Slaughter started New America, she saw that employees were carrying large vacation balances. So she has a use-it-or-lose it policy. On top of the normal three months off for parental leave, New America offers an extra six weeks of paid time off, to be used for any purpose. But the real point is this–you must use four weeks of the year, or it’s lost. You can only roll over two weeks into the following year. “I believe strongly that my employees will in fact be much better at their jobs if they take real time off, rest, do new things, read novels, or do whatever they want to recharge,” said Slaughter. “This way we change the incentives; you’d be stupid to leave that time on the table!”

Other employers, like CBS Interactive (TechRepublic’s parent company) have a mandatory shutdown between Christmas and New Year’s to help ensure that US employees take a break.

6. Make your case

When leave policies are not on the books or part of the workplace culture, Slaughter advises employees to propose their case to managers. Remember the “value of experimentation,” she said, and “approach your manager with the attitude: ‘I think I can do a better job for you if….I work from home one day a week. I come in late or leave early some number of days a week. I work out a job-share with a co-worker.’ Or, whatever would make the difference.” When you can present a good argument for why you’d do a better job, and propose a specific trial period, it’s difficult to not see the value in making the necessary adjustments.

7. Plan ahead

“Businesses routinely expect all managers to have succession plans in place in case they leave or are promoted,” said Slaughter. “So why shouldn’t managers be responsible for contingency planning on the assumption that all employees could be out from up to two weeks to three months?”

Cynthia Calvert, president of Workforce 21C, suggests that managers automatically create “work coverage plans” for every employee, to ensure that work will continue to be carried out smoothly in case of absences.

But the best thing for employees to do? “Know your rights,” said Steffeney. “And be prepared with a plan.”