Investing is the most powerful tool to build wealth, but it requires stomaching some risk. Thankfully, you don't have to be a stock-picking genius to grow your money in the markets. In fact, legendary investor Warren Buffett suggests everyday investors stick to low-cost index funds. You can start investing in index funds directly through a mutual fund provider, in your retirement account, or by opening a brokerage account at an online investor like Wealthfront, Betterment, or Ellevest. Buffett is a huge fan of Vanguard, the creator of the index fund, for simple, low-cost, and high-performing options.