Growing up in a rough neighborhood in Queens, New York, Daymond John was taught that "me and my boys would all be dead or in jail by the time we were twenty-one," he writes in his new book "Powershift: Transform Any Situation, Close Any Deal, and Achieve Any Outcome."
Teenage John obviously "didn't like either one of those options." So he began to set goals and visualize his ideal future.
"I started when I was around 16 years old, after I read the book 'Think and Grow Rich' by Napoleon Hill," John tells CNBC Make It. (The famous 1937 classic includes lessons Hill learned from studying 500 millionaires — like Andrew Carnegie and Charlies Schwab — on how to build wealth and manage time).
"I would write [my goals] down and read them every single night before I go to bed, every single morning when I woke up," John says.
At 23, John started apparel company FUBU, selling his hats on street-corners in Queens and paying the bills by working at Red Lobster as a waiter on the side. Over the next decade, John grew his brand into a fashion empire (which would eventually be worth $6 billion, according to John).
It wasn't easy. Along the way, "I would always drift off," John tells CNBC Make It. But it was "those goals [that were] always bringing me back."
"I actually became the man that I thought I would be by the age of 30 by reading [my goals]," he says.
Here's how to set and live by goals, according to entrepreneur and "Shark Tank" star Daymond John.
Before starting the goal-setting process, John emphasizes in "Powershift" the importance of "understanding your 'why.'"
One of the biggest reasons people fall short of their goals "is simply that they don't take the time to think them through," John writes. "They put it out there that they want to make partner, or they want to make a million dollars, or they want to start this or that business, but they don't stop to think about why they want these things."
John first heard the concept articulated by Simon Sinek, who wrote a book called "Start with Why" and spoke about "finding your 'why'" in a 2014 TED talk. John said he was inspired by one of Sinek's lines: "People don't buy what you do. People buy why you do it." Your "why" determines the magnitude of your success, according to John.
"This idea [of knowing your 'why'] should be the foundation for everything you do," John writes. "Otherwise, you could be working hard and busting your a--, but really have no idea where you're trying to go."
And John notes your "why" can change, as his did.
When John was younger, his "why" was solely to make money, he says. But with FUBU, that shifted to creating a brand "all about inclusion and inspiration," he writes. Most recently his "why" has become educating and inspiring other entrepreneurs.
Your goals should be achievable within a certain time frame — they should have an "expiration date," according to John.
Citing "Think and Grow Rich," John suggests writing your goals "in six-month tranches," he tells CNBC Make It. Once you achieve them, "then you reset them."
You should also set larger goals with longer "two-year, five-year, 10-year and 20-year" deadlines, he says.
"For as long as I can remember, I've had a goal in mind. But these goals weren't just things I'd think about in the back of my mind. I'd actually write them down," John says in his book.
John says he reads each of his goals every morning and every night.
"I close my eyes and visualize each goal, almost like I'm willing it into view," he says in his book. "And even with my eyes closed, I'm able to clearly see where I am and where I need to be."
For instance, John once wrote down the goal of cashing a check for $102,345,086.32.
"That's an actual number I wrote down with all my other goals, as a way to visualize what I wanted in a way that seemed real, not arbitrary. I'd rather hit a specific target than aim for a general area – that's why the bull's eye is worth more than all those other rings on the target," he says in his book.
"If you're not in charge of the goals you're putting in your mind, and you let other people set goals for you, you give away power," John tells CNBC Make It.
"Because people say [it] can't be done — I've never heard that," John says. "You can't get that job or become a gazillionaire. 'Not in our family. Never been done before. You're going to embarrass yourself or you're going to embarrass us.'
"And we allow people to set different goals and take the power away from us," he says.
John learned to shut out noise, stick to his goals and visualize the success he desired, despite how anyone else felt about it.
"I eventually learned that to achieve big things in life, you need to set big goals," he writes in his book. "It's as simple as that."
Disclosure: CNBC owns the exclusive off-network cable rights to ABC's "Shark Tank."