U.S. president and five-star general Dwight Eisenhower used a simple device to illustrate the art of leadership. Laying an ordinary piece of string on a table, he'd illustrate how you could easily pull it in any direction.

Then he'd push it and show how it didn't go anywhere, saying that people were the same way.

Leadership at any successful organization needs to be plainly defined. Here's how I see it:

-- L is for loyalty. A leader must be loyal to the organization, and leave no question that he or she is committed to its success. Loyalty is the distinguishing quality of winners. That goes for everyone -- entrepreneurs, owners, managers and employees, no exceptions. A leader models loyalty so that it works top down, bottom up and side-to-side, and at all times.

-- E is for enthusiasm. Leaders know that enthusiasm is contagious, and they help spread it around. If you are excited about hitting the pavement every day, it will show. And that generates enthusiasm among your employees and customers.

There is one thing more contagious than enthusiasm, and that is the lack of enthusiasm.

Focus on the positive, even if it is a small thing. Train your brain to look for the silver lining, and then be amazed at how your improved attitude leads to enthusiasm that permeates the workplace.

-- A is for adversity. Truly effective leaders accept adversity as a condition of doing business. I have never met a successful person who hasn't had to overcome either a little or a lot of adversity. Don't be afraid of adversity -- handled properly, it makes you stronger. It helps you grow. Problems and people can't stop you. The only thing that can stop you is YOU.

-- D is for determination. Determined people, particularly determined leaders, possess the stamina and courage to pursue their ambitions despite criticism, ridicule or unfavorable circumstances. In fact, discouragement usually spurs them on to greater things. When they get discouraged, they recognize that in order to get different results, some change is required. Determined people also exhibit another "D" trait: discipline.

-- E is for example. We lead by example, whether in business, family or friendships. It doesn't matter if you're raising children or managing people, setting a good example is one of the most important leadership skills. You have to practice what you preach. How you conduct yourself says more than any instructions you may give. Set high personal standards and expect the same from your staff.

-- R is for resilience. Failure is all too common in business and in life. Anyone who has ever run a business wakes up regularly with nightmares about the what-ifs. Successful people are resilient. They don't let hard times turn into end times. Let them lead to your best times.

-- S is for sincerity. Say what you mean and mean what you say. "Go team go!" only works if you are sincerely committed to what you are doing.

-- H is for heart. A good decision must factor in the human element. When your head and heart say the same thing, you can bet it's the right answer. There's no denying the heart of a leader. Use your head, to be sure, but don't ignore what your heart is telling you.

-- I is for integrity. Integrity begins at the top. Leaders must set the example -- inspiring employees to do what is right, rather than what is easy. We must clearly define what is expected throughout the organization, ensuring that integrity is first and foremost in our decision-making. Enduring leaders know that integrity is not optional.

-- P is for purpose. Leaders think in terms of goals. There isn't a college football coach with a greater sense of purpose than Lou Holtz. He proved it at Notre Dame, Arkansas, the University of Minnesota and a host of other universities. Did you know that Lou once coached the New York Jets? He left the job after only eight months. Why? Because, as Lou told me, he came to the job "without a clear sense of purpose. Absent a focus of my own, I couldn't give one to the team. I was embarrassed by my inability to provide them with proper leadership. So I left." Few leaders are as honest.

Mackay's Moral: Great leaders know how to "spell out" goals and expectations.

In the book "The World According to Mr. Rogers," children's television star Fred Rogers passed along the following story about the value of making mistakes.

An apprentice carpenter applied for a position with a master carpenter. During the interview process, the master became very aware of the young worker's pride -- everything he'd done was perfect. Finally, the master carpenter asked the apprentice if he had ever made a mistake, to which the young man proudly said no. The confident young man thought the job was his.

However, to his surprise, the master carpenter said he would not be hiring the skillful apprentice. The reason: That when he did make a mistake, he would have no idea how to fix it.

I completely agree with that hiring decision. It's OK to make mistakes, but you have to learn from them. If you just keep making the same mistakes, one of two things is happening: You are not paying attention, or you just don't care.

So often, the person who never makes a mistake takes orders from the person who does. The risk-takers tend to become the entrepreneurs and managers. And some of the mistakes they have made are costly and embarrassing. But the lessons they learned taught them how to "fix it," as Mr. Rogers would say.

Thomas Watson Sr., the founder of IBM, said of mistakes: "You can be discouraged by failure or you can learn from it."

The person who makes a mistake and then makes an excuse for it is actually making two mistakes. People respect those who take responsibility for their own errors. Regardless, you will be better off admitting a gaffe than spending considerably more energy trying to avoid the subject. If you seize the opportunity to learn what went wrong, you'll be a lot less likely to make the same mistake again.

To paraphrase the words of our favorite baseball philosopher Yogi Berra, "Don't make the wrong mistakes."

Embrace mistakes as opportunities to grow. In today's business climate, people are making split-second decisions. That makes for a high likelihood of mistakes. But keep in mind that if you're not making mistakes, you're not taking any risks. And that could mean you're not making progress.

"Mistakes are the downside of risk-taking. And it seems as if we've become very unwilling to tolerate mistakes," said my friend William R. Brody, former president of Johns Hopkins University. "Being risk-averse is hurting our global competitiveness and stagnating our incomes."

Managers have a specific role in dealing with staff mistakes. You want your staff to make as few mistakes as possible. But workers do need to know when they make mistakes so that they can learn and grow in the workplace.

As a manager, you need to think about the problem and assess how important the mistake is. If the mistake was made out of lack of awareness, let the person know what has happened, and explore whether he or she knows how to prevent it in the future. If the mistake was made out of carelessness, then talk to your employee. Find out if something is distracting him or her. If the employee is feeling overworked, see if you can provide some help.

Remember, when an employee fails, you share the blame, just as you share the credit for your workers' successes. Make sure that you don't abdicate your responsibility. Verify that you have communicated clearly so that employees know what you expect. And most importantly, be available to help -- because if you fail your employees, you are making the worst mistake.

Mackay's Moral: If you don't learn from your mistakes, there's no sense making them.

A man went to a rabbi and asked, "Rabbi, you're a wise man, how is it that you're wise?"

The rabbi replied, "Study and hard work."

Then the man asked, "What made you study and work hard?"

The rabbi replied, "A lot of experience."

Then the man asked, "And how'd you get a lot of experience?"

The rabbi answered, "I had good judgment."

And the man then asked, "What gave you good judgment?"

The rabbi said, "A lot of bad experiences."

Over the past few years I've written three columns on street smarts. After all my years in business, I'm afraid I just scratched the surface. Here are some more ideas:

Idea No. 1 -- A plan isn't a plan until you have a backup plan. You may have mapped everything out, but what if something unexpected happens? I can't emphasize enough how important backup plans are. You should always have a plan B and possibly plans C and D. The bigger the deal or event, the more detailed your backup plans should be.

Next Idea -- Use your network for referrals to save money. More than once, I've been able to negotiate better deals by offering referrals. The results can be even better than bartering.

For example, I was 29 years old and couldn't afford to build a new envelope manufacturing plant. But because I had a network, I was able to find a builder and guarantee I would get him other business. I got him four other buildings, and he gave me a down and dirty price. I did the same with my architect. Talk about a win-win situation -- and an excellent way to put your network to work.

Next Idea -- Follow the fleet. Starting out in sales can be tough. When I began selling envelopes at age 21, I pored through the phone book for a week, looking for leads. Then my dad suggested that I might try to ingratiate myself with one of the battle-scarred veterans of the envelope wars on the sales staff.

I did exactly that, and we drove to our arch-competitor's plant. We parked about 50 yards away from the shipping department and waited until one of its trucks began to pull out to make the day's deliveries. The rest of the day we followed that truck. What leads we got! What a treasure-trove of information! What would you give to have your biggest competitor's customer list?

Next Idea -- Don't forget people from your past. My father taught me the importance of a good memory. What he meant by that is no one becomes successful on his or her own. There are a lot of people who help you. You never want to forget those people.

For example, I had a friend from kindergarten who went on to become a successful entrepreneur. He gave me a lot of advice and counsel when I started my envelope manufacturing company. I stayed in touch with him. One day, I picked up a newspaper and read that my friend had just become CEO of the largest retailer in the United States. Is it any wonder that it became one of my largest envelope accounts?

Next Idea -- There is a right way and a wrong way to lose a customer. Let's face it, everyone loses customers. The trick is to position yourself to get that customer back someday in case their new supplier doesn't perform.

Immediately schedule a one-on-one meeting with that customer. Never do it by telephone or email or text. Do it in person. Tell them how much you have appreciated their business in the past and that you will move mountains so that it will be a seamless transition to their new supplier. Also, tell them that you will always be ready to help out in any way whatsoever in the future.

Next Idea -- Nothing motivates people like crisp, cold, hard cash. I have found there is no better way to reward people, including sales managers, entrepreneurs, project leaders and so on.

For many decades, I used to hand out cash at our company sales meetings as a reward for attracting new accounts. The place got very hushed as I pulled out all those brand-new $100 bills. In short, the results are stupendous.

Mackay's Moral: Let street smarts help you navigate the bumps in the road.