So far, we've discussed renting out your garage, your spare room, and your imaginary duplex. Now let's talk about renting out the things in your home. Sure, you could just sell that hedge trimmer that you never use, but why do that when you could rent it out for a fixed price per day and have it make money for you indefinitely?
This might sound crazy, but people actually do this and make money from it. You could hire out your camera, your lawnmower, your barbecue set - anything you could think of that someone else might want to use for a few days or a set period of time. Websites like Fatllama.com and RentNotBuy.com give you the platform to do it, and you set the price. Just remember to charge a deposit to put people off the idea of stealing it.