When it came time to plan her company's retreat last fall, Kara Goldin decided to splurge. Goldin, the founder and CEO of flavored-water purveyor Hint, could have just scheduled a bunch of meetings at her San Francisco headquarters. But instead, she spent a considerable (if undisclosed) amount to fly her 49 employees to Scottsdale, Arizona, where they spent half a week hiking, whitewater rafting, and having other outdoor fun.

There was an immediate payoff, says Goldin. "People jumped right back into work when it was over," she recalls. "And then on the weekly conference calls, people were communicating more."

The Hint field trip helps explain why, after falling into disfavor among bean counters during the Great Recession, the company-retreat business is on an upswing. While few estimates exist for the overall size of the industry, hotel executives as well as retreat facilitators say it is growing rapidly. Employee training and team meetings are now some of the primary drivers of growth for corporate junkets, according to the American Express Global Business Travel unit.

When done right, a retreat can pay off with better employee morale and increased engagement. But retreats are an investment of time and money: You'll lose hours or days of your employees' labor, and you'll need to pay for what they're doing instead. If you absolutely need to keep costs down, you could get away with a brown-bag lunch and a day of activities in the office for a little more than $20 a head, says Marilyn Suttle, a career coach and retreat facilitator.

Yet most agree you'll get the best long-term results if you can gather employees off-site. "It shifts people out of automatic pilot and keeps away distractions," Suttle says. You can do this in your home city, of course; if you want to splurge for travel and overnight accommodations, expect to spend at least four figures per attendee.

Once you've set your budget, what can you do to ensure you get the most bang for your buck? For starters, pick one or two areas to focus on during the retreat. For Goldin, that was bringing her employees--many of whom work remotely-- closer together.

Ben Brooks, the founder and CEO of employee-engagement service Pilot, picks tasks for his workers to complete during retreats. "I think of them as a hackathon for nontechnical people," he says. At one event, employees edited video scripts, something that could have taken weeks in the office. "It left people with a sense of accomplishment and clarity," he says.

Still, be careful not to cram too much into your retreat. When the meter is running, it's tempting to keep your employees busy. But that defeats the purpose of getting away from the office. "If you're just herding a mass of people through a rigorous schedule, they'll go home after it's over and not engage," says Stephen Milbank, co-founder of business-to-business technology startup Button.

As he's learned, play goes a long way. At Button's regular Hamptons retreats, employees do a team cook-off, preparing meals on a tight budget. The results have ranged from burgers and pizza to elaborate three-course meals--and helped Button's bosses see how their employees work.

"We set a maximum spending limit for food but did not address bartering or foraging," Milbank says of the cook-offs. "Some saw the rules as defined borders, while others saw the rules as a jumping-off point for creativity. The competition helped me understand the types of environments different team members need to thrive." That's what I call a recipe for retreat success.