If you have a certain set of skills for example "Knitting", you can knit up some clothing and then sell them online at Ebay.
If you love taking photographs, then you could sell your photos online at https://submit.shutterstock.com/.
If you love writing then you can write up an ebook and sell them online as well.
If you love blogging, then you can setup a blog with adsense and earn money when people visit your blog and checks out the ads displayed.