The secret to success? Make laziness embarrassing.

FORTUNE — Like many writers, I’ve been kicking around an idea for a novel for years. I wrote a chunk of my tale — about a small-town high school basketball team, a championship, and a mystery — during a less busy time in my life years ago. I’d been jotting down ideas on how to finish it since 2011. But I couldn’t build momentum. I’d write a bit, then abandon the project for months.

I know why. I like to get paid for my work, and I like my work to be read. Writing a novel means investing serious time in something that may or may not ever result in publication, let alone revenue. Finishing it with no promise of external validation would require serious willpower. That’s a problem, since I already expend most of the willpower the universe grants me trying not to grab snacks hourly from the kitchen next to my home office. Consequently, with other people and projects competing for my attention, the novel always fell to the bottom of my list.

I needed a way to get it to the top.

This is a problem many people face, I learned while writing about workday schedules for my recent book. We have grand ideas for where to take our careers someday, but immediate deadlines or meetings or aggressive coworkers always seem to take precedence on Monday morning. Internal motivation is powerful, but it’s easier to say no to ourselves rather than the rest of the world.

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So what do successful people do? They create external motivations for things they want to do but that life has a way of crowding out. They create accountability systems that boost important but not urgent items to the top of their priority lists — ideally in a way that makes failure really uncomfortable. Effective people know that we succeed when success seems like the easiest choice.

Nika Stewart, for instance, owns Ghost Tweeting, a New Jersey-based social media marketing business. She’s also part of an accountability group called the 7-Figure Club, which is sponsored by Savor the Success, a network of women entrepreneurs. Every Monday, each entrepreneur checks in online to set a weekly goal that will advance her toward her annual goals. Then on Friday, everyone checks back in to say if she did or didn’t meet her goal. If Stewart’s weekly goal, shared with the group on Monday, was to send out 10 proposals, she tells me, “Thursday night, if I didn’t do it, I might stay up and do it.” Why? She doesn’t want to look lazy in front of people whose opinion she cares about.

I knew I needed an accountability system for myself, or my novel would never get written. Late last year, I read a Fortune article by Katherine Reynolds Lewis called “Career coaches: When are they worth their salt?” I emailed Katherine to congratulate her on her article, and we got to chatting about whether she’d ever hire a career coach, and whether it might be a good idea for me. She told me, “I don’t want to pay someone to tell me to do the things I know I should be doing to advance my career goals … but haven’t found the willpower to do. I think what I really need is a writing buddy who will hold me accountable to the goals I set.”

Sensing an opportunity, I proposed. Would she be my writing buddy? She accepted. We talked through my goal (finishing the novel) and how I intended to accomplish that (write 2,000 words per week). I’d check in on Friday to say whether I’d done it.

I’m almost embarrassed to say how effective this little shift in approach was. Being accountable to Katherine made me want to write 2,000 words, just so I could email her and say I’d written them. There weren’t any real consequences to failing, but the part of my brain that learned to turn in papers on time in school years ago leapt to attention once it had an assignment.

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“Write 2,000 words” got a spot on my to-do list along with assignments from paying clients. In 10 weeks, I had enough words (20,000) to have a sense of how I intended to shape the second half of the book. I carved out a day to figure out where various chunks should go, and at that point, the momentum of having an actual story compelled me to write the rest of it.

I cranked up to 5,000 words or more per week, and started beginning my days with novel writing, rather than figuring out where novel writing would fit in with the rest of my life. By April 15, I had my draft.

There’s still a lot of editing work to be done, of course, but I find turning something into something better much less daunting than turning nothing into something. An accountability system got me over the nothing-to-something hurdle. And, as Katherine would point out, it was much less expensive than a career coach.

What project in your life could benefit from an accountability partner?

Laura Vanderkam is a regular contributor to and the author of What the Most Successful People Do At Work, out April 23.

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