There are two broad ways:-

The High Level:

1. Learn relentlessly. Read books and books on success, people skills and anything that might have some inkling of strand of wisdom about success and wealth. Especially read the biographies of successful people. In his autobiography, Mark Cuban talks about how we would buy and read any book on business that he thought might help. The $15 he'd spend was a fraction of the wisdom he picked up was worth. Drew Houston of Dropbox talks about how he would spend every weekend reading books on business, sales, marketing, all day long. Every weekend.
2. Become a people person. This is a learnable skill or skills. No one is born a great salesperson. There may be people (like athletics) with better inborn abilities (outgoing, etc). But the best learn, they read, they study, and they practice, relentlessly. A lot of times, those with the best given talent, don't end up being the top in the field, because at the start, it comes easy to them. The ones that have to work at, work relentlessly and don't ever get complacent. And then one morning, they wake up and the effortlessness at sales or marketing or leadership that they never thought they would achieve, they now embody.
3. Work hard. As an employer, one of the things that stands out the most with employee is a good work ethic. It's worth it's weight in gold. Drop your expectations and ego, and put your nose to the grind and good things will happen.
4. Take risks. Not dumb, fickle risks and not gambles. But smart, calculated risks where you have a good chance at succeeding. You won't always succeed, but you will learn a huge amount in the process and you will garner an enormous amount of respect from people in doing so. 

The Nitty Gritty:

1. Get a job in a high growth industry. This is where the quick money and the opportunities are. There's a saying how everything rises with the tide. When you're in a fast growth industry (or company), the tide is rising.
2. Work for the best and most recognizable company you can work for. This gives you instant credibility. Starting as an intern at a recognizable company will get you opportunities right away.
3. Become an expert. Pick an area within your industry and learn it inside and out. Start writing answers on the topic in Quora, start a blog on the topic, network with other experts. You'll find pretty quickly that this type of knowledge and expertise will lead to a huge array of options.
4. Create multiple income streams. Start writing, consulting, tutoring, fixing things, just get busy with a second source of revenue. This will get you hungry for more and you'll double your learning. You'll see that a job tutoring on the side, can lead to starting your own tutoring company on the side. Your marketing consulting job can lead to writing Amazon books on marketing.
5. Be too busy to spend money. Feel like you spend too much money? Feel like you don't save enough or at all? Get busy working on everything, your job, learning, networking, consulting, projects, side jobs, overtime at work and you'll find out you won't spend a fraction of the amount of money than before.
6. Finally, start a company. Name a billionaire who didn't start a company. Yes, there are a few. But they ended up running the company they joined (Sheryl Sandberg, Steve Ballmer, Eric Schmidt). Starting a company may seem completely out of reach and unfathomable, but when you've done all the preceding steps, it will be the most logical next one. Successful companies don't start out with 50 employees and a $10M in revenue, they start out small, tiny and scrappy. They start out in their dorm rooms or their parents garages or spare bedrooms. The founders beg, borrow and steal(well, I don't recommend you steal. :-) ) to get what they need. Michael Dell started his company by hacking together computers in his dorm room. Walmart started as a single variety store in Newport, Arkansas. Ever hear of Newport, Arkansas? Yeah, me neither. Richard Branson started out selling records by mail, one at a time. Don't look at the most successful people and companies and see where they ended up or you'll be overwhelmed. Look where they started and you'll see how it's achievable. 

All credit to Evan Asano