Escaping the corporate world and becoming an entrepreneur is certainly an attractive proposition for anyone who relishes the idea of being their own boss, but before taking this plunge, it's important to acknowledge just how hard it can be to launch a successful startup.

Running your own business today is so difficult, in fact, that some have compared it to managing one of the top firms on Wall Street

"I tell anyone who asks that being an entrepreneur is tougher than running Merrill Lynch," Sallie Krawcheck, owner of professional women's network Ellevate, wrote in a recent article posted on LinkedIn.

Krawcheck would know. In addition to having held the title of CEO of Sanford Bernstein and Smith Barney, she also ran Merrill Lynch Wealth Management for more than two years.

The first practical advice she gives to anyone even considering pursuing a career as an entrepreneur is to take a long, hard look at your finances to see whether you can afford to invest heavily in your business while earning little or no income.

"As the founder of a start-up, it’s not about how much cash you can make, but how little you can make and for how long. Firstly, that cash can help the business to be successful; and, secondly, if you are going to be successful, the value of that dollar working in the start-up is worth massively more than in your bank account. So before you make the switch, do the math and shore up the bank account."

Another consideration Krawcheck highlights involves doing some introspective research. Before jumping headfirst into entrepreneurship, she writes, it's important to question your true motivations for doing so. Is it your passion for creating something out of nothing that's driving you, or the "idealized portrait" of life as an entrepreneur?

Even if you are financially prepared to start your company, and you feel you're doing it for all the right reasons, it's safe to assume that, to some degree, you will fail. The silver lining, according to Krawcheck, is that all entrepreneurs fail at one point or another.

"It's just a matter of what you fail at and how quickly you recover," she writes. "And you will be rejected; it's just a matter of getting past the rejections."