How about some things that are not so quid pro quo. Let's go further outside the box, shall we?
Look around your home. See anything that you haven't used for a year and won't in the near future? You know, you can sell it online. Maybe you could use the money from that stuff to buy items in auctions or online auctions. Then, sell it for a profit and do it again. There are bargains galore out there. If you have an interest in this, you can make some great money. A lot of people are doing it.
Another thing that people are doing for a side hustle is making videos and posting them on social media.
This is a fun way to spend your extra time. It's different from the previous ways because it is not a straight forward ‘if you do this, you get that’. It’s a way to eventually make extra money.
However, in the beginning, statistically speaking, you won't. However, if you practice, practice and practice, which would be fun because you are passionate about it, it could pay off huge.
Speaking of paying off huge, create an online store front. There are several companies that will help you with this. They can provide the template for a fee. Figure out what it is that you want to sell, something that you love ie: car parts, computer parts, candy, etc. Start approaching companies that manufacture these and learn how you can become a dealer. You see, manufacturers are interested in manufacturing, not necessarily selling to the general public. They look for help by offering opportunities to a middle man.
That's where you could come in. I suggest that you look for companies where you could drop ship their products.
This means that you never have to hold an inventory. You just have to provide a website that offers their products to the general public. You become their marketing and sales team. Your investment is only what it costs for the website.
By building this kind of a company, you would be building an actual residual income. It would also be somewhat passive income depending on the amount of customer service that you would have to provide.