When you work for yourself, can you take time off?

December 16, 2011, 2:18 PM UTC

FORTUNE — Not many job categories are growing in today’s economy, but here’s one that is: the number of workers calling themselves “free agents.” According to temp staffing agency Kelly Services, more than four in 10 workers call themselves “free agents,” feeling unattached, long term, to any employer. This is up from 26% in 2008. People flit between organizations and — often — spend significant time working for themselves.

There are many upsides to calling yourself boss. The downside? Every year, around the holidays, entrepreneurs learn (and relearn, as the case may be) that it’s tough to take even a week or two off, let alone a longer absence, like a maternity leave or sabbatical.

While corporations dangle paid vacation as a perk, as James Sutton, a self-employed psychologist in Pleasanton, Texas puts it, “the self-employed person pays for their ‘fun’ twice: the cost of the time off, and the revenue lost from not working.”

It’s tempting to just keep grinding away. But that’s counter-productive. Sutton claims that “some of my best ideas and marketing approaches came when my mind was refreshed and ‘idle,’” and many other free agents report the same thing. Here are a few strategies for taking time off from business owners who’ve done it:

Plan ahead. Way ahead.

Figure out your 2012 travel plans by the end of 2011. Knowing your vacation times at least a few months in advance lets you build that lack of availability into your client proposals and plan your pipeline accordingly. Says Tim Parkin, president of Parkin Web Development in Orlando, Florida, “last minute trips make it difficult to adequately prepare and give notice to your clients. It’s unfair to both parties.”

Knowing your schedule ahead of time also lets you plan for some long days before and after, and arrange employee schedules with that in mind. Parkin notes that clients who learn of your vacation plans “might have immediate requests (‘Can you do XYZ before you leave?’), which is why more notice is better.”

Watch your business cycle.

If you run a retail business, forget about starting Christmas vacation before Christmas. Mark Aselstine, who co-owns a wine club called Uncorked Ventures with his brother-in-law, notes that “50% of our sales typically occur between Thanksgiving and Christmas Day.” 2010 was their first in business, “and we didn’t have a real plan and ended up, frankly, not doing a good job seeing family, or getting customer orders delivered in a timely manner.”

This year, the rest of the family will start Christmas without them, and Aselstine and his brother-in-law will take off on the night of the 23rd. At that point, it’s too late to get wine delivered before the 25th, and with January being a slow month for wine, they won’t have to hurry back.

Get help.

Meghan Ely, owner of OFD Consulting, a Virginia-based wedding marketing firm, took an eight-day trip to Ireland last September with her husband. “Prior to leaving, I trained one of my staff members essentially how to ‘be me,’” she says, answering emails, taking the first few steps with prospects and the like.

Don’t have staff? Doctors cover each other’s shifts for vacations, and if you have a colleague you admire and trust, you could try referring work over there during your time off — particularly if you plan to take a longer leave. You could also ask a trusted friend or family member to check your email and voice mail and call your hotel if anything disastrous happens.

Consider shorter, more frequent breaks.

Gaurav Sharma, who now runs the startup RightBuy.com, used to run a web consulting company. “I took a week off last year and even though I planned it well, a few clients were frustrated,” he says, and did not become repeat customers. Now he sticks to long weekends.

Others squeeze in a week by thinking outside the usual calendar categories. Tim Pacileo, owner of TheBoardRoomAdvisors, a marketing firm, often takes his vacation from, say, Wednesday to Wednesday. If clients think on a weekly cycle, this allows you to never actually skip a week. “It’s easier on my customers and doesn’t affect my income stream as much,” he says.

Schedule short “work breaks” on your vacation.

Brad Friedman, an attorney who now works in social media marketing, says that “My type-A personality wouldn’t possibly let me completely shut down for an entire week.” So what he does is “set a schedule before I leave town. That schedule provides me with some time every day, or every other day, to check email and phone messages. I try to limit this ‘work time’ to no more than an hour a day. Frankly, this tip helps me relax on the vacation much more than if I would try to totally cut myself off from work for a whole week.”

But even keeping all this in mind, happy business owners say that you sometimes just have to go for it. Taking time off is a risk, but so is running a business in general. Paige Arnof-Fenn, founder of the consulting and marketing firm Mavens and Moguls, took a month off for her 40th birthday, staying in a rustic farmhouse overseas that had no Internet access or cell phone reception. She told everyone months ahead of time, and then just went. She enjoyed the experience so much that she and her husband will be taking another month off to go to Australia and New Zealand in 2012.

“Not a milestone birthday for either of us but just a way to celebrate our lives,” she says. She and her husband have lost several relatives in the past few years, and the lesson they are drawing from it is to “not … wait for an excuse to take time off” — even if it takes some effort to scale back up when you return.