I had a few rentals while I was flying full time: 2 condos and a Tri-plex.
The condos would net $200 per month each and the Tri-plex about $1k.
Lots of work and money upgrading and managing but when I sold everything
after 5 years it was payback time, good profits.
Started a charter boat company after the last condo was gone, took tourists
and local out on sight seeing cruises in Fort Lauderdale, all boat expenses
deducted on regular income taxes.
Also done day-trading as a side gig, got adrenaline kicks out of it and made
a few $$.
Now retired and lazy but the side hustles paid off.