OfferUp.com. If you don't have the energy to hold a yard sale, OfferUp may be the next best, profitable thing. Sell one thing at a time. Take a picture of what you have, put down a price and hopefully somebody nearby will see it online, love it enough to buy it, send you a note and you'll meet – in a public place, OfferUp's website recommends – and you can get your cash for whatever you're selling. Of course, you might ask how this is different than selling on, say, the ever-popular Craigslist. Some users claim that it's an easier site to post on, and members have profiles, so you can rate each other and get a better sense that people are who they say they are, which isn't always the case on Craigslist. Nevertheless, you'd still do well to use common sense and buy and sell OfferUp items in public places rather than at someone's home or in the dark woods.
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.