How a person defines success is a subjective thing, but likely involves some combination of financial independence, loving relationships, a solid education, and a rewarding career. Over the years, I have been fortunate to interview hundreds of founders and executives who fit this bill. Collectively, they tend to exhibit a handful of habits that set them apart from average achievers.

1. They keep a to-do list.

It's not rocket science, but a great many of the high-achieving individuals I've written about keep track of what needs to get done every day. Putting these things to paper (or screen) keeps them front and center, where they are more likely to be accomplished. "Each evening, I write a to-do list, organized by order of importance, and I make sure to accomplish the first two items at the start of the next day," says Nicole Smartt, author of From Receptionist to Boss and shareholder and vice president of Star Staffing, which is included on the Inc. 5000 list of America's fastest-growing companies.

2. They keep their minds uncluttered.

Successful people don't ruminate on negative experiences or conversations, but learn and adjust as needed and concentrate on what's happening in the here and now. Researchers have found that mindfulness is the best antidote to brooding, self-criticism, and negative emotions--all of which are counterproductive to success.

3. They take risks.

Taking risks often leads to failure, but successful people learn from their mistakes to become better versions of themselves. "You may think you know what your next step should be, but when you take it and fail, the lesson you learn ultimately ends up being what was standing between you and success," says Mattias Lepp, founder of indoor gardening solutions company Click and Grow.

4. They can make decisions without having all the data.

While information has its place, often 100 percent certainty isn't possible, at least if moving forward is the desired result. "I rarely find that I have all the information I want to make a truly informed decision," says Mark Gainey, co-founder and CEO of Strava, a social network for athletes. "And while it's never good to make a decision in a vacuum, I have found that luck favors the person willing to make a decision with an incomplete set of data rather than being greedy and waiting too long for all the information to surface."

5. They're generous.

In a way, this is like investing in good karma. Think of the miserly people you know. Are they the first people who come to mind in terms of people you want to help?

6. They exercise every day.

Take a look at the biggest names in business and you'll see people who work on staying fit. People like Mark Cuban, Elon Musk, and Tim Cook spend their valuable time burning calories and building muscle. Successful people understand that the discipline of fitness is a potent stress reliever, mind declutterer, and way to subconsciously solve difficult problems.

7. They expect good things to happen.

Richard Wiseman, a psychologist at the University of Hertfordshire in England, has conducted research working with hundreds of exceptionally lucky and unlucky people. One trait of the former group: They expect good fortune. "These expectations become self-fulfilling prophecies by helping lucky people persist in the face of failure, and shape their interactions with others in a positive way," he writes.

8. They take quiet time every day.

Whether it's meditation or prayer, successful people take time to still their minds. "When we look beyond the headlines and history books at the personal habits of great historical figures, we see a pattern of self-imposed solitude," says Dr. Randall Bell, author of Me We Be Do: The Four Cornerstones of Success. "It allows us to see the bigger picture. In practice, cultivating this habit means completely turning off all technology for part of each day."

9. They count their blessings.

Complainers are not winners. "Devoting your first five or 10 minutes of every day to being grateful for the new day in front of you and the abilities, gifts, and talents that you have been blessed with to create your own destiny and wealth truly makes a difference in long-term success," says Aurea McGarry, Emmy Award-winning TV show host, producer, and director, CEO and founder of Live Your Legacy Summits, and president and founder of Legacy Maker Entrepreneur coaching systems, which has trained more than a million entrepreneurs nationwide. "It's a true statement that it's not happy people who are grateful, but grateful people who are happy. Happiness is part of success and if you're happy, you will be much more productive and it will be contagious to those who work with you and are helping you achieve your goals in your business."

10. They work on getting smarter.

Whether it's reading or listening to podcasts, successful people continually work on self-improvement by accessing the wisdom of others. Connor Wilson, co-founder and COO of Thursday Boot Company, a premium men's and women's boots and accessories brand, reads history. "It's a conscious way to slow down, reflect on the big picture, and learn about how decisions are made in the real world," he says. "It's also a way to stay personally inspired. Human history is full of individuals who transformed the world through little more than grit and imagination. That's a great regular reminder for anyone trying to do the same."

11. They invest heavily in relationships.

A fascinating 75-year longitudinal study of 268 Harvard undergraduate men found the most powerful factor associated with health and happiness in old age: the warmth of a person's relationships. Truly successful people do not achieve great things by prioritizing work over family. Rather, they tend to banish devices from the dinner table where they find themselves most evenings.