After reading RDPD, I felt confident that I could generate some passive income to supplement my full-time job as a clinical psychologist (which I do actually love).

Circle Prospecting Around Listings You or Other Agents in Your Office have sold or around active buyers you're working with is the best way to expand your database supplemented with Calling your entire database at least quarterly with updates about the local market and how it can affect their future home goals.

Private lending is a passive, high yielding investment, that needs the tax shelter provided by an IRA.The potential down-side would be encountered if your deal required additional funding and your "private lender" would want to supplement personal funds to those of the IRA. 

I'm working full time as a healthcare professional and looking to supplement my income to save for future investments and have some travel money!

If so, keeping the forced air for downstairs may leak enough heat up to supplement a mini split in the upstairs unit.

For a tenant that doesn't have enough income, but who's parent is willing to supplement and guarantee?

I enjoy development, but would like to supplement my income by investing for myself rather than only working to make other people the profit.

@Bruce Woodruff and @Scott Mac you have to be careful with mini splits in Chicago since the temperature can get below the operating minimum for these systems to heat.... maybe if you are using it as a supplemental heater it would be ok?

Airbnb is great supplemental income for us.

That being said I am now thinking if I could do just 2 flips a year and make 15-20k each that would supplement my handyman business income well and could pay the bills.