If you have a spare bedroom, you can find a roommate or list the space on AirBnB for travelers. Having a roommate is the more passive of the two, as being an Airbnb host will require more work in the form of turning over the room between stays. This is a super painless way to earn $500 to $1,000 a month without much effort – you may even be able to cover your mortgage payment with this extra income!
Or, there is another theory for your primary salary – generate enough to have a little excess cash flow, but do it at a place that you can work stress free and have time to dabble in other projects. A good friend of mine has this setup – he works 10-5 and makes $50,000 a year. This allows him to easily cover all of his expenses, but the shorter hours and flexibility in his job allows him to pursue his secondary income generating ideas!
If you watched the video, he goes into a discussion about shocks (about 8 minutes in) like bad investments but how they don't really matter as much if r (rate of return) is greater than g, the rate of economic growth. If r = 5% and g = 1%, then you can lose 80% (the difference) and still be ahead because the return on the remaining 20% has paced with economic growth.
Most of us think of investment income as just the cash flow we get from bank interest, bonds, share dividends and property rents, some of which comes via a super pension. But a more complete view is to also consider how growing the value of your investments can add to your spending potential. This total return approach generates income from both income and growth to optimise spending from your portfolio across all market cycles, aligning cheap and expensive investments to your goals.