Forget the conventional wisdom that a safe approach is best when it comes to gearing up for retirement. It's become increasingly clear that putting cash in stocks for the long term (as opposed to holding more investment in bonds) is the smarter route.

Americans aren't so hot when it comes to planning for their financial future. Consider that in 2014, they left a staggering $24 billion in retirement money on the table by not contributing to their 401(k)s--even as personal savings saw a spike of 0.9 percent the previous year.

"You should be hitched to U.S. stocks, and the long-term growth of American business," says Jane Bryant Quinn, a best-selling author, entrepreneur, and award-winning personal finance journalist.

Having written columns for such publications as Newsweek and The Washington Post, Quinn set her sights on investing for retirement--or, as she prosaically puts it, how to prevent a scenario in which her money runs out before she does.

In her new book How to Make Your Money Last: The Indispensable Retirement Guide (Simon and Schuster), out January 5, Quinn demystifies the retirement planning process by outlining the dos and don'ts of social security, pay annuities, and reverse mortgages, for example. 

Here are some of her retirement tips for business owners.

1. On the advantages of the SEP IRA, or the solo 401(k) plan. 

Entrepreneurs stand to benefit from setting up a corporate savings "vehicle," Quinn explains, whether that be a solo 401(k)--if the business has no employees--or an SEP IRA (Simplified Employee Pension Individual Retirement Arrangement), which would cover both the employer and his or her employees.

She cautions, however, that while investing for growth is a smart strategy, entrepreneurs need to play it safer than most. 

"Your investments should be more conservative than if you were the executive of an existing company because you're more at risk," she says. "Basically, by owning your own company, you are owning a very risky stock, so if you're balancing your investments, the stock that you buy should not also be risky stocks." 

By starting a stock index fund, business owners can sit back and run their company, without having to worry about keeping track of those investments. It may also be a good idea to keep a large percentage of investments in the safer CDs (certificates of deposit) or in treasuries. 

2. On the rapid rise of financial technology startups.

While many are skeptical of automated financial advisers that manage funds (without any human interaction), Quinn is bullish on their market proposition.

"I love these automated financial advisers--and not just for Millennials," she says. "Once you have the money, if you're focusing on your business [and] you don't have the time to manage it, I think these robo-advisers are a good choice." She nods specifically to Betterment's new 401(k) tool for small businesses, which the company plans to roll out this year.

Consumers should be wary when approaching any financial planner that earns a commission, however, since he or she may not necessarily have your best interests at heart.

3. On what the next administration should do to make preparing for retirement easier.

With U.S. presidential elections coming up in November, Quinn sees one clear wrong that ought to be rectified by the next administration.

"I think it is a scandal that an automatic payroll deduction plan is not available to every single worker in this country," she says. "Your employment status should not make the difference between whether you have health insurance or not, and your employment status should not make the difference for whether you can make an automatic savings plan."

While she concedes that President Obama's myRA plan was a good start, there are many limitations worth noting. A myRA fund cannot exceed $15,000, for example, and earns the same interest rate as the Government Securities Fund, which is low (about 3 percent) compared with the annual return of the S&P 500 Index. 

4. On false assumptions about women's investing.

Women may earn just 81 cents to the male dollar, according to recent gender pay gap data, but that doesn't mean they're not as good at investing their money. In fact, the opposite may be true. 

"That's a huge miss," Quinn says. "The data consistently shows that women save a higher percentage of their paychecks than men do, even though on average they are earning less." 

The assumption isn't just inaccurate, it's actually dangerous. "Men don't magically make money better. In fact, some of them are terrible at it. Men don't want to think the same way women do. Men and women take equal kinds of risks," said Quinn.