Real estate investing
Founder, RealEstateInvesting.org Investor, Speaker, Author. Eric Retired in 2015 at the age of 30 with a multi six-figure income entirely from rental property.
Next you need to add value. Usually this is done with renovations but there are dozens of ways to add value!
Once any upgrades are complete, it's time to rent any vacant units and bump rents in any occupied units. This helps increase the value as well.
If you added a lot of value, you can cash-out and get all (or most) of that money back to do it again!