Power Players

This unglamorous job set Warren Buffett up for success—here are 4 others that can do the same for you

Paul Morigi | Getty Images | Fortune | Time Inc

We all want the same things in our professional and personal lives — to be a well-rounded and capable person, to have an impressive resume, more career opportunities, more money in the bank. Essentially, to live a successful life.

But studies have found that most young people lack the critical skills for success. And no, I'm not referring to all those advanced tech skills; rather, it's the soft skills like creativity, communication, time-management, emotional intelligence and adaptability that are often the most overlooked.

While researching for my book, "Quitterproof: The 5 Beliefs of Highly Successful People," I found that some of the wealthiest and most driven individuals developed the critical soft skills that got them to where they are today by working not-so-glamorous jobs (some of which had very little to do with the industry they're currently in).

No matter where you are in your career, there are benefits to taking on a job that's unrelated to your passions or career goals. You can even do them on the side and earn some extra cash in the process.

While they might seem mundane and boring, here are five types of jobs that can teach you the valuable skills that will set you apart from your competition:

1. Delivery work

Essential skills you learn on the job: Time management, problem-solving, communication, self-management

One of Warren Buffett's first jobs as a teenager was delivering newspapers. He would wake up at 4:30 a.m. to deliver copies of The Washington Post.

The Berkshire Hathaway CEO challenged himself to find more efficient and faster ways to complete his job. Then, he created a system to track when the houses along his route had magazine subscriptions expiring and sold new subscriptions on the side, along with calendars.

Delivering papers instilled the importance of hard work and reliability, Buffett said in an interview with The Globalist. "You learn a lot about human nature when you deliver papers," he added. "For one thing, you learn you have to pay for them each month. Whether the customers pay you or not. You have to collect the money."

Food delivery services are also a great place to start if you want to get into the business. Some companies even allow you to set your own schedule, which is especially helpful if you're considering doing it as a side hustle.

2. Assistant work

Soft skills you learn on the job: Attention to detail, relationship-building, correspondence, research, coordination

The idea of getting coffee or organizing files for someone else might not sound appealing if you have dreams of becoming the next Jeff Bezos.

But being someone's assistant can be a lot like a paid apprenticeship. It's a chance to shadow a successful person and learn their tricks of the trade — often, things they don't teach you in school. Working as an assistant can also give you access to a network of important contacts.

Ruth Bader Ginsburg worked as a law clerk for two years after graduating from Columbia Law School in 1959. That job led to research associate positions, a professorship and various other career-climbing opportunities on her way to the Supreme Court.

3. Selling at a food stand or shop

Soft skills you learn on the job: Customer service, communication, patience, efficiency, multitasking, product knowledge

In some cases, it might be a better idea to skip the unpaid internship and make a few extra bucks selling at a food stand on a busy street or in a food court at the mall.

Universities and recruiters are far more likely to be impressed by a stint at a hot-dog stand than an eight-week coding camp, Jenny Anderson, a writer who covers the science of learning, noted in a Quartz article. Former Goldman Sachs CEO Lloyd Blankfein did just that: His first job was selling hot dogs in Yankee Stadium.

Barack Obama even worked at a Baskin-Robbins in Honolulu before he became president of the United States. Scooping ice cream all day might sound like a mindless task, but as Sue Thirlwall, Baskin-Robbins' former brand operating officer, told the L.A. Times: the business can actually teach employees "crucial presidential skills," such as how to be efficient, handle consumer care in real time and keep calm under pressure.

"The crew member who communicates effectively is both a diplomat and a terrific brand ambassador," she said.

4. Teaching

Soft skills you learn on the job: Patience, writing, mentoring, creativity, conflict-management, emotional intelligence

As Roman philosopher Seneca once said, "While we teach, we learn."

Without a doubt, teachers have one of the hardest jobs. Students can be tough to handle, and those challenges often involve having to deal with parents as well.

But getting to see the difference you make in a young person's life can be a rewarding experience. Doing so requires patience and empathy, which will help sharpen your emotional intelligence skills. More importantly, teaching strengthens your ability to explain complex things in a way that's easy to understand — and that skill is transferable to any job.

Teachers are also encouraged to flex their creativity skills. This certainly helped best-selling authors like J.K. Rowling, who worked as an English teacher in Portugal, and Stephen King, who held teaching stint at the Hampden Academy in Hampden, Maine. (King wrote "Salem's Lot" while living in a trailer and teaching during the day).

A bachelor's degree and certification is usually the requirement if you want to teach, but tutoring is another option if you have deep knowledge and expertise in a specific topic.

5. Selling your own crafts

Soft skills you learn on the job: Entrepreneurship, communication, product knowledge, negotiation, self-management

There's nothing exciting about raising chickens and selling eggs in your backyard, but that's exactly what Charles Schwab, founder of Charles Schwab Corporation, did when he was 11 years old.

The job taught him how to be a better negotiator: When it was time for the hens to "retire," he would negotiate a good price for them as fryers, Schwab said in an interview with Entrepreneur.

Working on the farm and selling to locals also taught him the value of hard work and money: "I was cautioned about not wasting money and the importance of stretching a dollar as far as it could go," he said. "There was a real incentive to work hard and earn money so I wouldn't wind up without any financial resources."

Of course, you don't have to work on a farm and sell eggs to adopt these important skills and traits. These days, you can sell almost any product or service through online platforms like eBay and Etsy.

Kyle Young is a freelance creative writer and author of "Quitterproof: The 5 Beliefs of Highly Successful People." He has also written for Fast Company and Harvard Business Review. Follow him on Twitter here.

Don't miss:

Lana Del Rey reveals her early Craigslist side hustles and how she spent her first big paycheck
Lana Del Rey reveals her early Craigslist side hustles and how she spent her first big paycheck