If you have a background in website design, you have a huge client base, including website developers, who know how to create sites but not design them.
If your passion lies in visual themes, layouts, color palettes, and fonts, freelance web designing is a good online business you can consider.
The best part is that for this job, you need little to no education. In this field, it is your experience that matters the most. In fact, if you assemble a wonderful portfolio of your best work, it can help you attract clients all by itself.