For many 20-somethings, retirement is the last thing on their minds. But starting to invest early can set you up for financial success — especially if you want to retire early.

On Monday, Insider hosted an Instagram Live event focused on early retirement with Soledad Fernandez Paulino, a financial educator and founder of the blog Wealth Para Todos. During the Re/Thinking Re/Tirement event, an attendee asked, “What is the best way to invest in my early 20s? Is there a particular formula for it?”

Fernandez Paulino provided a step-by-step method for investing in your 20s to be financially prepared for your future.

• Build a solid emergency fund

“Before you start investing aggressively, you want to make sure that you have an emergency fund. You want to have access to cash reserves,” Fernández Paulino said.

An emergency fund is money that you only tap into when you face an emergency, such as a job loss, large medical bill, or unexpected car repair. You don’t need to completely hold off on investing until you have an emergency fund — you just may not want to put all of your extra money into investments quite yet.

Traditionally, experts have advised that you keep three to six months of necessary expenses in an emergency fund. But some people prefer to set aside even more for a rainy day, maybe a year’s worth of expenses.

“It depends on the financial security you have in your life,” said Fernández Paulino. If you think you could find another job easily should you be laid off, you may only need a few months’ expenses in your emergency fund. But you may want more cash reserves if you think it would be hard to find a job quickly, or if you have kids or other dependents who rely on you financially.

• Pay off high-interest debt

Once you have an emergency fund, there’s one more important step before kicking your investment strategy into high gear: Paying down any high-interest debts. Fernández Paulino said they consider “high interest” to be anything that charges over 9% APR.

You might not need to put extra money toward your federal student loans or mortgage, which tend to charge lower interest rates. But credit cards and personal loans might be worth paying down sooner because they could charge higher rates than you’d earn by investing in the stock market.

• Find out if you have an employer retirement account

The first step in investing should be contributing to an employer retirement account if your company offers one. This could be a 401(k), 403(b), or 457(b), for example.

Fernández Paulino said this is an especially useful first step if your employer offers a match. For example, the company might contribute 100% of what you contribute, up to 3% of your paycheck. This way, you’re receiving free money toward retirement.