Another benefit of investing in rental properties is the loan pay down. If you obtain a loan to buy the property, each month your tenants are paying off part of the loan. Once the mortgage on the property has been paid off, your cash flow will increase dramatically, allowing your mediocre investment to skyrocket into a full-fledged retirement program.
This was a very inspirational article! I too spent 20+ years in a high-stress career selling a high-end product under a 100 percent commission plan; that is, no salary! I realized, after racking up millions of frequent flyer miles, that there had to be a better and less-stressful way of making a living. My goal was to design my own lifestyle free of corporate shackles, which required a pre-determined amount of passive income.
However, I think for those who are willing to do what it takes, the sky is the absolute limit. As an example, I’m trying to take a page out of FinancialSamauri’s book and create an online personal finance and investing blog. It is an enormous undertaking, and as a new blogger, there is a seemingly endless amount of work to be done. That said, I hope that one day I can not only generate some passive income from the hours of work I have put and will put into the project, but I hope to be able to help OTHERS reach their financial goals.
An obvious example is over exposure to bank stocks, which have been excellent investments for over a century.  Though a foundation of most portfolios, bank stocks do involve more risk at certain stages of the economic cycle than many realise.  Being less exposed to bank shares in the last few months could have preserved some capital.  So, a more diversified approach can help mitigate some of these risks.