Invest in Rental Properties What is it: Purchasing residential or commercial property to rent out to tenants is perhaps the most traditional form of real estate investing., 5 ways to invest in real estate include REITs, online real estate investing platforms, rental properties, flipping properties or renting a room., Investing in real estate is a great way to diversify your portfolio, but many don't know where to start. Learn about your options, how to invest, and the pros and cons., , , .