Write and publish an eBook. You don’t need a traditional publisher and financial backing to publish your own book anymore. In fact, Amazon.com makes it possible for you to publish your own eBook and sell it independently – with no financial investment on your part. And with Kindle eBook publishing, your book will appear on Kindle stores worldwide within 24-48 hours. Just be prepared to market it yourself on social media, your blog, or elsewhere if you expect to generate sales.
Monetize a hobby. While some hobbies actually cost money, others can be transformed into a profitable business venture. Ultimately, it depends on what your hobby is and how talented you are. You could turn your love of photography, for example, into a part-time gig taking family portraits and wedding photos or selling prints on Etsy or at arts fairs.