Mark Cuban, Richard Branson, and 24 other successful people share their best career advice for people in their 20s

Reuters/Olivia Harris

If clichés like "follow your passion," "give 110%," and "be true to yourself" just aren't cutting it for you anymore, we've got some fresh takes on how to get a head start on your career.

From "don't work too hard" to "relax," here are some of the best — and often unconventional — pieces of advice for people in their 20s from some super-successful people:

Sheryl Sandberg: There is no straight path to where you are going.

"As Pattie Sellers of Fortune Magazine says, careers are not ladders but jungle gyms," the Facebook COO wrote on Quora. "You don't have to have it all figured out."

Sandberg recommends having a long-term, abstract dream to work toward in addition to a more concrete 18-month plan. The long-term plan allows you to dream big while the short-term plan forces you to push yourself and think about how you want to get better over the next year and a half.

"Ask yourself how you can improve and what you're afraid to do," she said, adding "that's usually the thing you should try."

Warren Buffett: Exercise humility and restraint.

In a 2010 interview with Yahoo, the Berkshire Hathaway CEO said that the best advice he ever received was from Thomas Murphy, a Berkshire Hathaway board of directors member. He told Buffett:

Richard Branson: Never look back in regret — move on to the next thing.

Branson's mother taught him this.

"The amount of time people waste dwelling on failures, rather than putting that energy into another project, always amazes me," the billionaire Virgin Group founder and chairman told Good Entrepreneur. "I have fun running ALL the Virgin businesses — so a setback is never a bad experience, just a learning curve."