The cover story in the current issue of Fortune magazine is “The World’s 50 Greatest Leaders.” Once again, I didn’t make the cut. I suppose it’s possible that I’m number 51, but my guess is that I’m further down the list.

But the story got me thinking: what makes a great leader? What are the skills that the truly effective leaders possess?

There are many, to be sure. But in my experience—both as a leader and in working with leaders across the country—there are four foundational skills that all great leaders have developed, and continue to develop throughout their careers.

A great leader:

Creates

Leadership is an act of creation. A great leader creates a team, creates a vision, creates a plan. I’m not saying he or she necessarily does this alone, but a great leader creates. Even if a leader inherits a team, she re-creates it in a way that furthers the goal, the vision. More than one leadership guru has stated that creativity is the #1 skill that leaders need today (and tomorrow). What many people don’t realize is that it is a skill that can be learned, nurtured, and improved. Great leaders take the act of creation seriously, and strive consciously and continuously to develop their creative skills.

Communicates

A great leader is a great communicator. Whether they are communicating to the team, the stakeholders, or the public, great leaders have the ability to get their message across both clearly and compellingly. And the really great ones understand—and use—the unmatched power of humor.

Inspires

Team members follow a great leader not because they have to, not because they’re told to, but because they want to. Why? Because a great leader inspires them. A great leader makes them want to be better than they currently are. But let’s be clear—there’s more than one style of inspiration. You don’t have to be the bombastic football coach or the fire and brimstone preacher to be an inspirational leader. Mother Teresa never ranted in a locker room at halftime (to the best of my knowledge); Warren Buffett doesn’t thunder from the pulpit. But both have achieved remarkable results through inspiration.

Decides

When, as a television Executive Producer, I was leading my team, I thought of my leadership style as a “democratic dictatorship.” It was democratic in that everyone had input, everyone had a vote. But ultimately, the call came down to one person—me. I was the dictator. Sometimes my calls weren’t popular. Sometimes they may not have even been right. But sometimes (e.g., when it’s not possible to have all the information necessary, when your options are equally good—or equally egregious, or when you’re simply out of time), you can’t know the right decision, or there is no right decision. At those times, it’s more important that the leader make a decision than the right decision. A leader who makes the wrong decision is simply that: a leader who made a wrong decision. But a leader who makes no decision is no leader at all.