Plenty of companies pay lip service to the idea of corporate culture. But beyond mission statements and corporate training, many really don't spend much time thinking about their culture.

That can be a costly a mistake. Whether you manage your corporate culture or not your company is going to have one. And with 70 percent of employees reporting not feeling engaged at work, a coherent and purposeful culture can go a long way toward motivating your workforce. That's why successful companies like Zappos and REI put such emphasis on employee culture. In fact, SouthWest Airlines explicitly puts employees first, believing if the company treats employees right, then employees will treat customers right.

While there's no one 'correct' culture - every company has to decide what is right for them -- there are a few principles that companies with strong cultures follow, starting with these four:

1. Prescribe

It's important to choose what you want your culture to be and then attract people who want to work within that culture. Strong corporate cultures grow organically, but in a prescriptive way. Like any family, your work family shares idiosyncrasies, habits, and values. Who you choose to be part of this family will determine whether your culture will be either strong and productive or dysfunctional.

Zappos' CEO Tony Tseih learned this lesson the hard way. He watched the culture of LinkExchange, a startup he helped found, start to dissolve as the company grew. When he took the helm at Zappos, he was determined to make sure each employee was right for the culture. Potential hires start with a "cultural fit interview." If they aren't a right fit, no matter how talented, they don't move on in the hiring process. But it doesn't end there. After a few weeks of training, every new hire is offered money to leave. It's the ultimate test for separating out the truly committed.

2. Reinforce

Companies with coherent cultures are deliberate about cultivating and reinforcing their culture. They put elements in place that support organic growth in the direction they want. These can be informal activities such as company barbeques, or scavenger hunts, where managers and employees have an opportunity to get to know each other on a personal basis. Whatever the activity, managers know that these culture-building exercises are a priority.

Another important step is figuring out who your cultural catalysts are within the workforce. In every organization they are the people who love their company and what it's capable of achieving. They can be a manager, an administrative assistant, or an IT help desk employee. It doesn't matter what job they do, it's key to recognize them as one of your biggest assets. Uncover these catalysts and how you can best shine a spotlight on them, as well as how you can reward them.

3. Support

Leaders shape culture through their actions. We've all been in that company where the motto touted transparency, communication, and respect, but the managers held secretive closed-door meetings and belittled others behind their backs. People take their cues about how to behave not from words or mission statements, but from what is modeled by the leaders around them.

Virgin's Richard Branson and every one of his daredevil adventures is probably one of the most extreme examples of a company leader who models the culture by what he does. But all leaders have a role to play.

4. Repeat

Complacency might be the biggest pitfall to a thriving culture. Most people working in startups know that its culture needs to adapt as the company grows. But the culture of large companies also has to evolve in step with the market and customers.

IBM is a great example. The tech behemoth has had to reshape its culture three times during the past 20 years. Lou Gerstner saved the company from being broken up by shifting the culture from individualism and decentralization into one of integration. Sam Palmisano then put collaboration at the heart of the company. Now, Ginni Rometty is remaking IBM for the world of distributed data, software, and services, by focusing on agility and discovery.

It's not a question of whether you will have a company culture. It's a question of what company culture do you want? More than ever, culture will be a differentiator, so how will you shape yours?