If you have a propensity for writing and you can slay with your prose, consider writing an ebook. While the market has certainly become saturated as of late, books that help teach people about a technical topic still sell extremely well. This is a great source of passive income but does require a large amount of effort at the outset before any money is generated. 

It’s sometimes hard to comprehend just how much people love t-shirts. And with the right niche, marketing and tools, you can create an online t-shirt business that makes you extra money online while you sleep. (Even Bloomberg and Forbes feature stories from entrepreneurs who've done just that.) Services like TeeSpring make it easier than ever to create a t-shirt drop-shipping business where they handle the sales, printing, and shipping, and you’re only responsible for design and marketing. Or you can even buy into well-established franchise businesses like Rhea Lana that sell fashionable, affordable kids clothing and get the backing of a proven organization to fuel your online sales. For more tips, check out this simple guide to launching and marketing an online clothing store by my friends over at Selz.
Whether you have a website or are still dreaming up ideas for a blog, you can also look into affiliate marketing. With affiliate marketing, you partner with brands and businesses within the content of your website. If you mention a product or service, you link to that produce or service using a unique affiliate code you received when you signed up for that particular affiliate program. From there, you’ll make money any time someone buys a product or service through your link.
Using a food delivery service can’t necessarily earn you money, but it can help you save you money if you constantly find yourself throwing out half the food you buy. Food delivery services send a box of food every week with new, sometimes unique vegetables, meat, fruit, and so on. If you don’t have time to shop and want simple meal-prep that leads to a good meal, a food subscription service may be perfect for you.
If you’ve got a way with words and expertise in a niche, there are plenty of sites that will pay for articles and content you write. Think of the sites you read regularly. What can you contribute to them that would be interesting? Research your niche and then look for ways to pitch articles. Many sites will simply have a submission or contact link in the footer. To get started, check out my full guide to becoming a freelance writer on the side and then submit your articles to places like Instash, Listverse, A List Apart, International Living, FundsforWriters, and Textbroker.
So, I put together a free master course for you to take that spreads out all of the work involved in starting a blog, into a series of action-packed lessons. My free course breaks the entire process of starting a blog down into an incredibly simple 7-day process for going from 0 to brainstorming the best blog post ideas, publishing (and promoting) your first blog post in just 1 week. We also cover beginner and advanced ways to learn how to make money blogging in the course. I can't recommend it enough.

Upwork: This website offers a great marketplace for selling just about any professional service. You don't need a merchant account, website of your own or anything else for that matter. All you need to do is be able to provide a high-quality service at a reasonable price. But be informed, you will have to compete with many others that are constantly bidding on open jobs. 

– Project Payday is one of those sites that has testimonials of people who have earned thousands of dollars by getting paid to get trial offers. I’m not saying you’ll earn thousands, but it is legit and you can earn some extra cash. They assume that by paying you to do a free trial, you’ll either like the product and purchase it, or forget to cancel the trial and get charged for it. If you can keep track and cancel before you get charged (if you don’t want the product), then this is a great site for making some money.

Research other listings in your city on AirBnB and see what the going rate is for a place like yours. You could also just rent out a private room as well or even a bed in a shared room. In fact, that's how AirBnB got its start. However, you might find it hard in the beginning without reviews, but as long as you take really good care of your guests and provide a lot of value, the reviews will eventually come rolling in.

The audiobook industry is booming, yet only 5% of books ever get made into audio format. If you’ve got a background in acting, or if people have said you’ve got a voice made for the radio, you can make extra money recording audio versions of independent and popular books. Sites like ACX connect authors with audiobook performers. So, whether you’re an author looking for more ways to sell your book, or an actor/voice actor looking to make some extra income, you can sell your services online.

Earning by comments will require you to have your own Blogs and Websites. You will then share these dedicated domains (Owned by You) in the comment window. If an option to add your URL or website is not available, then you do not include links. You contact the site support first and get permission to share your URL. Oh, and NEVER share affiliate links in comments.

Rather than making money through subscriptions, YouTube channels are based on a traditional advertising system. Meaning the more viewers you get, the more you make. Once you’re approved for the YouTube Partner Program and can start including ads on your videos, with every 1,000 views, you will make approximately $2-$4. Which might not seem like a lot, but if you have 100 videos with 5,000 views a month each, that would be $1,000–$2,000 already. Just imagine if your videos start hitting millions of views!