Cultures don't emerge in a vacuum. They serve a purpose and, generally, come into being in response to stimuli from the boss.

For example, a boss who is constantly looking to pin blame on people shouldn't be surprised if a defensive, "cover your ass" culture comes into being. Especially in startups, where there is neither precedent nor ingrained tradition about "how we do things," the CEO--always a strong factor when it comes to influencing culture--will play an outsized role. (Hello, Uber.)

In truth, startups have a huge advantage over more established companies when it comes to culture: CEOs have a chance to shape the culture they want from the get-go. "You create culture through design," says Tim Brown, CEO and president of IDEO. When anthropologists describe cultures, they talk about customs and rituals, temples and marketplaces, and corporate culture is no different--but in a startup, you don't have to worry about layers of history.

Therefore, as Brown says, "Use design to create the instances, rituals, spaces, and tools that make up a culture." Design determines and dictates behavior--what you do at every interaction with customers, what must be done behind the scenes to prepare for those interactions--and behavior then shapes the culture.

Here are five things startups need to do to design a culture that works equally well both internally and externally, serving both customers and employees:

1. Hire people with soft skills.

People who rely more on attitude than aptitude will be the kind of go-getter that can figure out how to help whether it's in their job description or not, or whether it's in their wheelhouse or not, advises Carolyn Betts, founder and CEO of startup-focused Betts Recruiting.

"Startups have to be mindful in all their decisions, and hiring is no exception," Betts says. "Take time to see how a candidate responds under unusual circumstances by roleplaying a potential service issue."

2. Reward the right behaviors.

Incentives and punishments can support or erode a service design. Do you hail the hero who parachutes into a disastrous situation and fixes it? Or do you celebrate the engineer who makes sure that disasters never happen in the first place?

What you celebrate sends a powerful message about what is valued. People will seek the validation that comes from praise rather than think about what triggers it. And make sure celebration isn't a once-a-quarter thing: As Harvard Business School's Teresa Amabile has shown, a steady stream of small victories keeps motivation high.

3. Recognize that everyone has something to contribute.

"Everybody is an expert in their own way," says Victor Ermoli, dean of the School of Design at the Savannah College of Art and Design. "If you have five years of answering the phone in customer service, or five years of listening to customers at the cash register, nobody knows more than you [about that]. You are not the only person with knowledge, but that knowledge has to be valued and put to use."

4. Be aspirational.

Betts advises that you create a clear vision for both your company and your culture, and hire for where you want them both to go, rather than where you already are.

"If your vision clearly communicates your company's values and priorities, the culture, whether it's as specific as being rooted in the benefits offered or as ephemeral as the way people interact, will follow," she says.

5. Align culture and strategy.

Travelers are drawn to Southwest Airlines--once a scrappy, disruptive startup--not only for its low prices but also for its reputation as being a place where everybody chips in and is cheerful. The culture is manifested in the jokes (funny or not) flight attendants customarily broadcast before takeoff as much as it is in imploring passengers' assistance in getting the planes turned around fast for the next flight.

If your strategy is to disrupt, don't reward by-the-numbers rule-keepers. And vice versa: You don't want cowboys running a nuclear power plant.