WASHINGTON - MARCH 13:  Warren Buffett, chairman and CEO of Berkshire Hathaway Inc.

There’s certainly no shortage of advice about how to invest for a successful retirement. However, sometimes it can be hard to know who to believe. If you don’t have a trusted fiduciary financial advisor, the next best place to get advice is from those who have become multimillionaires themselves.

Popular financial icons like Warren Buffett, Suze Orman and Jim Cramer have all succeeded at earning and investing money, so it’s worth listening to advice they give general investors. Here’s a look at some advice for a prosperous retirement from some of the most well-known financial pundits.

Last updated: April 22, 2021

Warren Buffett, the storied "Oracle of Omaha," has given decades of investment advice to anyone who would listen. One of his most important pieces of advice for general investors, however, has been to simply buy index funds. Buffett has always had little faith in the ability of active money managers to outperform the S&P 500 index, so he has even instructed his trustee to invest 90% of his estate in index funds after he passes. This general advice he also considers to be appropriate for most investors.

In a mid-June 2020 interview on the Pivot Podcast, financial commentator Suze Orman pleaded with investors to use Roth accounts for their retirement savings. As Orman said, "Please, if you have the ability to do a Roth 401(k), 403(b), or a TSP, or a Roth IRA, those are the type of retirement accounts that you want to be in. Stay away from the traditional ones… where you get a tax write-off today but in the long run when you go to take your money out you’re going to have to pay taxes on it." Orman added, “With a Roth, you pay taxes today, and in the long run, when you take it out, it’s tax-free."

How can avoiding credit card debt set you up for retirement? By freeing up funds that you can use for savings and investment. According to Mark Cuban, "racking up credit card debt is the worst investment you can make." Any amount you have to pay in credit card interest is just wasted money that could have instead been used to fund your retirement accounts. If you carry a $10,000 balance on a credit card at the national average credit card interest rate of 14.75%, for example, you’re paying $1,475 per year in interest that could instead be used to invest for retirement.

Financial personality Dave Ramsey is a big believer in keeping things simple when it comes to saving for retirement. According to Ramsey, it’s far more important to invest consistently than it is to find some arcane, "get rich quick" scheme to hit your retirement goals. Ramsey recommends investing only when you’re ready financially, and that you never invest in something that you don’t understand. Under Ramsey’s retirement savings plan, the best way to reach your goals is to set aside 15% or more in Roth IRAs and pretax retirement accounts. To hit your retirement savings goals, Ramsey recommends investing in growth stock mutual funds with at least five years of consistent returns.

Kevin O’Leary, known as "Mr. Wonderful" on the popular series "Shark Tank," has no problem with people who enjoy day trading. However, if you’re looking to have a successful retirement, O’Leary stresses that you’ve got to have a long-term investment plan in place first. As quoted in The Penny Hoarder, O’Leary says, “My style is to put money aside for my whole life and leave it invested." Once you’ve got enough set aside for a financial base, you can use any extra money you have any way you want, including day trading.

Jim Cramer, the love-him-or-hate-him former hedge fund manager who hosts CNBC’s "Mad Money," is a stock trader by nature. However, for those saving for retirement, Cramer says to invest in index funds first. According to Cramer, the first $10,000 you set aside for your retirement savings should go toward index funds to form a base portfolio. After you’ve got that core investment in place, says Cramer, then you can begin to pick individual stocks for your retirement portfolio.

Robert Kiyosaki, author of the famous "Rich Dad" series, suggests that most people are saving for retirement the wrong way. According to Kiyosaki, rather than using traditional savings methods like IRAs and 401(k) plans, investors should be buying assets that generate cash flow and pay for their liabilities. Kiyosaki says that he and his wife "invest in assets that [generate] cash flow like real estate, oil wells, business and more. Each month, cash pours into our accounts from these investments, covering our expenses." Kiyosaki refers to this as "printing money," by finding ways to generate enough cash flow to cover all of his needs.

Suze Orman is a big fan of investing in Roth accounts for retirement, but for younger investors, she stresses that there’s an even more important first step. Before you invest at all, according to Orman, you should get rid of high-rate consumer debt, like credit cards and personal loans, and you should build up an eight-month emergency fund. As told to NextAdvisor, in partnership with Time Magazine, Orman suggests that after you’ve gotten your financial house in order, "I would be dollar-cost averaging every single month with a specific sum of money into the ETF with the symbol VTI. And do it at a discount brokerage firm where there are no commissions whatsoever.” VTI is the symbol for the Vanguard Total Stock Market Index, which includes stocks from the entire market.

Warren Buffett is so full of investment wisdom that every one of the spots on this list could be taken by his recommendations. However, two of his most essential are the one listed earlier — buy index funds — and this one — stay the course. As Buffett noted in his 2018 letter to shareholders, "Though markets are generally rational, they occasionally do crazy things." According to Buffett, investors need “an ability to both disregard mob fears or enthusiasms and to focus on a few simple fundamentals." In other words, invest for the long term and don’t get too caught up in the day-to-day emotions of the stock market.

As discussed above, Jim Cramer recommends that investors steer toward index funds before they pick up individual stocks in a retirement account. However, when that time comes, Cramer also has specific recommendations for what types of stocks you should own, and it depends on your age. “The younger you are, the more I’m begging you to take an aggressive stance on something speculative,” Cramer said on CNBC. For more senior investors, “I think you’ve got to try a stock like Johnson & Johnson, a company with a long track record of paying dividends.”

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After earning a B.A. in English with a Specialization in Business from UCLA, John Csiszar worked in the financial services industry as a registered representative for 18 years. Along the way, Csiszar earned both Certified Financial Planner and Registered Investment Adviser designations, in addition to being licensed as a life agent, while working for both a major Wall Street wirehouse and for his own investment advisory firm. During his time as an advisor, Csiszar managed over $100 million in client assets while providing individualized investment plans for hundreds of clients.