They are often used to supplement traditional financing and provide additional leverage for commercial real estate projects.

We BRRRR 8-10 per year and the flips supplement the money left in the BRRRRs.I personally care more about the location of the BRRRR rather than the money pulled out or the cash flow.

The STR is often a way to supplement the cost of ownership.

I currently have a full-time career as a senior engineer in the aerospace industry, but I’ve always been interested in real estate, and I view REI as a way to supplement my future retirement.I’m interested in initially doing fix and flips to build up capital for buy and hold investments in multi-family properties, and I have about $200K in home equity that I can leverage to get started.

We BRRRR 8-10 per year and the flips supplement and money left in the BRRRRs.

Use that to supplement your retirement and arent a RE junky.

I would suggest reading as many BP books as possible to supplement the BP forums.

After quitting I would want to be doing real estate deals more full time and do something more enjoyable to supplement my real estate income (maybe teaching or personal training- tbd).I’ve thought of buying 1-3 more properties within the next few years and then using the income from all my properties and job to hammer down the mortgages.

@Edward Schenkel Great advice above - What are your thoughts on supplementing with an umbrella policy? 

You can supplement the funds that you're taking out of your home through additional funds from hard money.