Look, I know it’s not always realistic to pull these off; I personally wouldn’t bother trying. But if you’ve got a ton of stuff lying around — not outright junk, but stuff you don’t need, like the aforementioned DVDs and kid’s clothes — it’s worth a try. Advertise on Craigslist and put up signs in your neighborhood, then come Saturday haul a table out to your driveway (assuming you have a driveway), load it up with stuff for sale, and take whatever you can get.
For example, you might take photos and have them available for a fee at sites such as shutterstock.com, smugmug.com, 500px.com, or istockphoto.com. Similarly, you can create and upload designs at sites such as zazzle.com and cafepress.com, where people can buy them imprinted on shirts, mugs, and so on. Similarly, you might write an e-book and sell it online, perhaps via Amazon.com's direct publishing service.
Tenants sometimes damage properties, and depending on local laws, they may be hard to get rid of. You'll be the one they call in the middle of the night if the roof is leaking, and you'll have to clean and perhaps freshen up the property between tenants. You can outsource much of this to a property management company, but it will take a cut of your income, often about 10%.
As an Instacart personal grocery shopper, you will actually be doing the grocery shopping yourself (so don’t crush anyone’s avocados!). Your compensation depends on several factors, like the average size of your orders and average number of miles driven per trip. You can also get tips in addition to the pay that comes directly from Instacart (most people report an average earnings rate of $15 per hour).