Individualized attention and coaching
JEI is a hospitality industry company, which means it starts behind the eight ball when it comes to employee participation and paycheck deferrals into 401(k)s. Industries where the average worker is paid less traditionally have lower participation—workers have a hard time setting money aside for retirement when other nearer-term goals like school tuition or saving for a house feel more pressing.
Some of the latest and most widely adopted 401(k) best practices for encouraging more savings, like auto-enrollment, weren't a viable fit for the company's culture, Swope said. "Those strategies felt big-brotherish to employees."
She found another way. By working with the 401(k) plan sponsor, she improved the plan's communications and made sure the enrollment process included a one-on-one meeting. "What really works well is empathy and caring for employees, eyeball to eyeball. We have a face-to-face interaction so they can talk about, "'Yes, I have aging parents' or, 'Yes, I went through a nasty divorce.'"
(Read more: Obamacare prices may lure employers)
Auto-enrollment, but with careful intent
The federal government opened the door to allow employers to automatically enroll employees in 401(k)s eight years ago, with the Pension Protection Act. Many plans established the enrollment at a fairly low 3 percent, fearing a big-brother backlash. But the best plans have auto-enrollment at 6 percent or higher. "That 3 percent was one of the travesties of the PPA because it led to a decrease of average savings rates," said David Blanchett, head of retirement research for Chicago-based Morningstar Investment Management.
The 3 percent essentially set a new voluntary norm, leading employees who might otherwise have saved 5-6 percent to believe that 3 percent was enough. In addition to a fairly high enrollment level, a plan should consider automatically enrolling everyone each year, similar to the open enrollment period for health care, not just new employees, Adams said. It's a concept that is still the exception to the rule with auto-enrollment, but it is being experimented with by some companies. Another feature is auto escalation, whereby the amount employees contribute increases with their raises.
A well-designed employer match
A big employer match might seem like the biggest deal, and it can make a big difference in totals with which people retire. "People understand it puts money in their pocket," Adams said.
But not all match schedules are created equal. "For companies that are unable to increase the amount of dollars allocated to making matching contributions, it may make sense to change the match schedule," Blanchett wrote in a soon-to-be released report on best practices, co-authored by Morningstar's large market practice leader, Nathan Voris.
For example, instead of matching 100 percent on the first 3 percent of employee deferrals, an employer could match 50 percent on the first 6 percent, or even 25 percent on the first 12 percent. These lower match schedules do a better job getting employees to "share the load" when it comes to funding retirement.
Have a good low-fee target date fund
Employers can't necessarily become investment experts, but should know enough to judge whether the investment company and advisor are working to give employees a good selection. The plan should guide them toward low-fee, passively managed investments—research has shown they perform the best for most investors over time.
One sign that your investment company is doing a good job: It offers a good target date fund among the investment options and presents it in such a way that employees are encouraged to see it as the basis of their retirement planning.
Target date funds typically use a group of underlying funds, shifting investors' mix as the investor ages—a shift that's known as the glide path. Target date funds that use index funds as the underlying investment are likely to be the least expensive, but whatever fund you chose, an employer should have a method for picking them and monitoring them.
Read more: The pros and cons of target date funds
"Target-date funds have layers of consideration, like the glide path and the underlying funds, that make due diligence difficult even for experts," said Blanchett. Morningstar ranks target date funds. San Diego-based retirement data company BrightScope offers a report, Popping the Hood, that analyzes target date fund families.
The report includes 48 fund families and 425 different funds. The number of funds is one indication of how large the universe of target date funds has grown and how widely they are being adopted by 401(k) plan sponsors. The other is the assets in them: They are projected to reach $2 trillion by 2020, compared with $502 billion in 2012, according to BrightScope.
—By Elizabeth MacBride, Special to CNBC.com.