Leadership is always a work in progress, as bosses learn from both their successes and their failures, and use the lessons they learn to modify their approach. Consultants Jack Zenger and Joseph Folkman recently shared a study they conducted with more than 330,000 bosses, peers, and subordinates.

These are the top 7 skills that Zenger and Folkman found leaders need to demonstrate if they want to succeed. Which ones do you excel in, and which need a little more work?

1. Drive

The most-effective leaders demonstrate incredible drive, motivating their team to persevere--even when they don't feel like they can. Showing this kind of fierce commitment to completing your goal is absolutely necessary for successfully finishing on time, in any industry.

2. Communication, often and usefully

Communication is an extremely powerful tool for any leader to wield, especially if done right and with lots of punch. The best leaders communicate to inspire and provide direction, to boost morale, and also to give valuable feedback to their people.

3. Innovation

Being innovative means that you're always a little bit ahead of the curve; you're always onto the next big thing before it's widely discovered and practiced. That kind of frontier-pushing attitude can be very helpful when it comes to encouraging your team to undertake tasks that seem a little out of the ordinary.

4. Expertise

While not every leader has a specific skill that they practice at work, it's pretty common for a leader to demonstrate one area where they possess particular expertise. In fact, having a "strong point" is super important for your team to be able to understand your worth and where you come from.

5. Development of others

Self-focus is important, but reaching beyond yourself in order to help develop other members of your team is very important in terms of overall growth. A leader committed to the team is a leader who cares for others--not just for themselves.

6. Problem solving

Analyzing problems, assessing the situation, and being able to successfully offer a solution is vital to leadership. Doing it effectively, and with results that count, is a huge part of leading very well.

7. Inspiration

Maybe the most important aspect of leadership is inspiration: the ability of a leader to inspire and motivate others to reach their own potential for the good of their company, and for the good of themselves. Being an inspirational figure is more than a job--it's a trait that can be applied to one's entire life--and it's something only the best of leaders possess.