Brooke Dixon has worked as a freelance software developer for years while raising his two daughters. During that time, he’s written millions of lines of code — and created his own informal code of conduct.

The code is intended as much for his clients as for himself. In part, Dixon, 42, uses the code to slow down the process so a project and its goals are clearly defined at the start. Rules and guidelines can “establish a platform of communication,” he says.

In a business world filled with ambiguity, creating clarity around your ethical or behavioral standards can seem like a quaint notion from a bygone era. Yet freelancers and independent contractors need these “rules of engagement” to establish boundaries and general “rules of the road,” says Sara Horowitz, president of the Freelancers Union.

The contingent workforce is growing rapidly, as companies supplement their full-time staff and keep costs in check by hiring temps, adjuncts, and consultants. A report by MBO Partners predicts a 35% spike in the independent workforce by 2018, while a study from Intuit concludes that in the United States, the share of contingent workers within the workforce will surpass 40% by 2020.

Independent contractors have begun to ask the Freelancers Union to develop a code that addresses how the business world ought to relate to them. “We will start the conversation” on topics around what it means to be a good freelancer and how payment should work, Horowitz says. The organization expects to develop a code to help freelancers work with one another and with businesses later this year.

Ethical exemplars are often difficult to describe but easy to spot. “Be a mensch, a really decent human being,” says Laura Pincus Hartman, a professor of business ethics at the DePaul University Drieshaus College of Business in Chicago. “Treat people fairly and justly,” and be willing to walk away from clients or deals that feel like they’re somehow related to The Wolf of Wall Street.

Many professional associations have developed ethical codes, from the American Academy of Actuaries to the National Association of Realtors, and the American Translators Association, all of which address client confidentiality and negotiation for recognition. These codes serve as starting points and can be adapted to fit an individual’s brand and needs.

Those who work in multiple jurisdictions — whether it’s Texas and Oklahoma, New York and New Jersey, or simply two hospitals with different ethical guidelines — may need room for variation. “Most audiologists are subject simultaneously to multiple standards of professional conduct; standards that can and do overlap,” writes Heather Bupp, an attorney at the American Speech -Language Hearing Association.

Management research scholar Mary Gentile uses guiding principles when she works as a consultant or speaker, and finds they make managing multiple clients and her job at Babson College easier. Principles or a code of conduct give professionals a chance to anticipate and rehearse for situations and conflict. “It’s a good idea to pre-script yourself.”

“I have this implicit code that I haven’t set down,” says Gentile, who is the author of Giving Voice to Values, a book that helps individuals speak up about moral issues. One principle is “assume nothing,” which showed up on a sticker on her desk when she worked at the Harvard Business School. “Don’t assume the best or worst. Keep eyes open and be alert,” she said.

This worked for her at a time when it seemed like she was not going to be paid for work she had done. “Part of me wanted to go to the place of blame and rage,” she recalled. Instead, she asked a few questions and discovered, “I simply got lost in the bureaucracy. Not assuming the worst, I was able to get what I was due.”

Gentile also believes in transparency and consistency on the rates she charges for speeches or consulting gigs on leadership and management education. She sets a corporate rate, a nonprofit rate, and an academic one, and then has a conversation with prospective clients. “Because you’ve named it, they usually will do their best,” she says. The alternative, varying rates all the time, is not fair to you and may give clients the impression you’re unfair or playing favorites, she adds.

Dixon, who is co-founder of temporary jobs site Hourly, drew on a book called Fool’s Rules, the staff handbook for the Motley Fool, where he previously worked for nearly five years. “What I do is sort of an adaptation from the time I was there,” he says. Dixon says he wants to avoid “being burned” or being left unpaid by a client and also hopes to put clients at ease that he is not taking advantage of them while he juggles his responsibilities as a father. “I’m more interested in how well the relationship lasts rather than how fast I can do the project,” he says.

“I over-communicate beforehand,” he says. “Invest in the setup,” and establish expectations. That way, “everybody’s on the same page before the project’s even started.”