Mark Cuban shares his top 5 tips for 20-somethings

After he received his bachelor's degree from Indiana University in 1981, Mark Cuban followed some friends to Dallas.

He remembers that when he first moved into their apartment, things were so cramped that he'd come in at night after bartending and have to sleep either on the couch or, if that was occupied, the floor. He kept his belongings in a heap.

Cuban didn't have much of a technology background but landed a job selling PC software. He performed well but his boss fired him for disobeying an order. Left with no savings but a strong clientele and an interest in the business, Cuban founded his own software distribution company, MicroSolutions. He and his business partner faced some difficulty along the way - like when a receptionist embezzled and ran away with $83,000 - but they outperformed the competition.

In 1990, when Cuban was 31, he sold MicroSolutions to H&R Block for $6 million and made about $2 million for himself after taxes. It was the first big win of his career, which would lead to his becoming a billionaire investor, entrepreneur, and owner of the Dallas Mavericks.

Cuban wrote a blog post in June 2009 (also included in his book "How to Win at the Sport of Business") meant to inspire young people trying to establish their careers in a world that had been ravaged by the Great Recession. The economy has significantly improved since then, but the lessons Cuban drew from his own experience are just as valid. We've summarized them below.

1. Live cheaply.

You don't need to sleep on the floor of a gross apartment with a bunch of your buddies, but don't let a focus on your outward appearance distract you from your financial obligations.

"It doesn't matter where you live," Cuban writes. "It doesn't matter how you live. It doesn't matter what car you drive. It doesn't matter what kind of clothes you wear."

When you're starting out, prioritize building a financial cushion. Use your 20s to pay off student loan debt, not accumulate credit card debt. Learn how to ignore the attraction of some unnecessary luxury, and instead build savings you can fall back on. You'll thank yourself later.

"The more you stress over bills, the more difficult it is to focus on your goals," he writes. "The cheaper you can live, the greater your options."

2. Take chances.

You shouldn't expect to land your dream job straight out of college, Cuban says. Be open. And if it takes you awhile to find a decent job, don't let your ego keep you from a low-skilled gig in the meantime. If you need to run a cash register or wait tables to pay your bills for a few months, that's fine.

Once you land your first job, you may find after a few months that it's not a good fit, Cuban says. That's fine, too. Look for something else.

"Finding the right job is a lot like dating," he writes. "It's hard until you start; then when you start, it's great until it's not. Then it's frustrating as hell until you get it right. But when you do, it all comes together."

3. Find a job you love.

Cuban says there's an easy way to tell if you've found a job that can help you build a career.

"If it matters how much you get paid, you are not in a job you really love," he writes. This doesn't mean that you should not strive to make as much money as possible, but you need to prioritize your passion over your paycheck if you want to put yourself on a rewarding career path that allows you to thrive.

"If you love what you do so much that you are willing to continue to live like a student in order to be able to stay in the job, you have found your calling," Cuban writes.

4. Be the best you can be.

Once you've found your calling, whatever it is, you should have only one goal: "to be the best in the world at it," Cuban says.

He doesn't mean that in a shallow, motivational-speaker way, either. He believes that the only way to become exceptional is to give your job absolutely everything you've got, and to live in a state of constant self-improvement.

You'll know that you're making progress not when you feel like you're at the top, but when demand for your services increases, whether within or outside of your company. Cuban writes that "rather than trying to convince people you are the best, let the quality of your work do the talking."

5. Be optimistic from the moment you wake up.

"You are going to screw up," Cuban writes. "We all do. I can't tell you how many times I did and continue to."

But you're going to need to learn to let little things go and see your failures as learning experiences. You'll experience negative emotions, but you'll need to let them pass through you rather than cripple you.

Tell yourself that "you're going to enjoy all the bullsh-- you have to deal with as you chase your goals and dreams, because you want to remember them all," Cuban writes. "Each and every experience will serve as motivation and provide great memories when you finally make it all happen."