I’ve had a 30-year love-hate relationship with mission statements. I’ve read thousands. I love it when a mission statement defines a business so well that it feels like strategy—and that does happen—and I hate it when a mission statement is generic, stale, and completely useless. Do a mission statement only if you are going to use it well.

Done right, your company’s mission statement defines the company’s goals, ethics, culture, and norms for decision-making. The best mission statements define these goals in at least three dimensions: what the company does for its customers, what it does for its employees, and what it does for its owners. Some of the best mission statements also include fourth and fifth dimensions: what the company does for its community, and for the world.

Here’s how to develop a useful mission statement for your business:

Keep Your Essential Story in Mind

Your essential business story should not be part of your mission statement—but do think it through: Imagine a real person deciding to buy what you sell. Imagine why she wants it, how she finds you, and what buying from you does for her. The more concrete the story, the better. (And keep that in mind for the actual mission statement wording as well: “The more concrete, the better.”)

What You Do For Your Customers

Start your mission statement with the good you do. Use your market-defining story to highlight whatever it is that makes your business special for your target customer.

Don’t undervalue your business: You don’t have to cure cancer or stop global climate change to be doing good. Offering trustworthy auto repair, for example, narrowed down to your specialty in your neighborhood with your unique policies, is doing something good. So is offering excellent slow food in your neighborhood, with emphasis on organic and local, at a price premium.

This is a part of your mission statement, and a pretty crucial part at that—write it down.

If your business is good for the world, incorporate that here too. But such claims need to be meaningful, and distinguishable from all the other businesses. Add the words “clean” or “green” if that’s really true and you keep to it rigorously. Don’t just say it, especially if it isn’t important or always true.

What You Do For Employees

These days, good businesses want to be good for their employees. If you’re “hard numbers”-oriented, keeping employees is better for the bottom line than turnover. And if you’re interested in culture and employee happiness, then defining what your business offers its employees is an obvious part of your strategy.

My recommendation is that you don’t assert how the business is good for employees—you define it here and then forever after make it true.

Qualities like fairness, diversity, respect for ideas and creativity, training, tools, empowerment, and the like, really matter. However, since every business in existence at least says it prioritizes those things, strive for a differentiator and a way to make the general goals more concrete and specific. While I consulted for Apple Computer, for example, that business differentiated its goals of training and empowering employees by bringing in high-quality educators and presenters to help improve employees’ business expertise. That’s the kind of specificity you should include in your mission statement.

With this part of the mission statement, there’s a built-in dilemma. On the one hand, it’s good for everybody involved to use the mission statement to establish what you want for your employees. On the other hand, it’s hard to do that without sounding like every other business. Stating that you value fair compensation, room to grow, training, a healthy, creative work environment, and respect for diversity is probably a good idea, even if that part of your mission statement isn’t unique. That’s because the mission statement can serve as a reminder—for owners, supervisors, and workers—and as a lever for self-enforcement.

If you have a special view on your relationship with employees, write it into the mission statement. If your business is friendly to families, or to remote virtual workplaces, put that into your mission.

Add what Your Business Does for its Owners

In business school we learned that the mission of management is to enhance the value of the stock. And shares of stock are ownership. Some would say that a business exists to enhance the financial position of its owners, and maybe it does. However, only a small subset of all businesses are about the buzzwords of “share value” and “return on investment.”

In the early years of my business I wanted peace of mind about cash flow more than growth, and I wanted growth more than profits. So I wrote that into my mission statement. And at one point I realized I was also establishing a place where I was happy to be working, with people I wanted to work with; so I wrote that into my mission statement, too.

Discuss, digest, cut, polish, review, revise

With every draft of a mission statement, before you settle, read it again and ask yourself this: Can anybody recognize your business from its mission statement? Does your mission statement distinguish your business from others like it? Would it be impossible to guess that it applies to your business instead of one of its competitors? If it isn’t clear that it’s your business, then it isn’t working.

Then read it again and edit it. Cut down the wordiness. Good mission statements serve multiple functions, define objectives, and live for a long time. So edit. This step is worth it.

As you edit, keep a sharp eye out for common buzzwords and hype. Cut whatever isn’t unique to your business, except for those special elements that—unique or not—can serve as long-term rules and reminders.

Read other companies’ mission statements, but write a statement that is about you and not some other company. Make sure you actually believe in what you’re writing—your customers and your employees will soon spot a lie.

Then listen. Show drafts to others, ask their opinions, and really listen. Don’t argue, don’t convince them, just listen. And then edit again.

And, for the rest of your business’s life, review and revise it as needed. As with everything in a business plan, your mission statement should never get written in stone, and, much less, stashed in a drawer. Use it or lose it. Review and revise as necessary, because change is constant.