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.
While writing also falls under the category of an actual work at home job, it can be great for extra cash, too. Particularly content sites. These are sites that post writing assignments for any of their approved writers to grab, and for most you only need average writing skill to become an approved writer. While the pay isn't fantastic, if you can write fast, you can for sure earn substantial extra money. Most of these sites will pay a penny per word or more:
This is a venture that is growing rapidly. You can create videos in just about any area that you like — music, tutorials, opinions, comedy, movie reviews — anything you want . . . then put them on YouTube. You can then attach Google AdSense to the videos, which will overlay your videos with automatic ads. When viewers click on those ads, you will earn money from AdSense.
 @dasjung It sounds like you paid a lot for your education, as did I. But you got to face it, today’s technology allows the average Joe to accomplish a comparable logo with much less effort than you or I could put into it, and the savings outweighs the extra benefit of our knowledge. We, as designers, have been out done. It is time to go back to school, unfortunately… 
Work remotely for a call center. Because many call center jobs are location independent, finding work in this field is an easy way to earn some money from home. Dozens of sites list job openings for call-center representatives, including and Meanwhile, you should check local job listings for openings and opportunities as well.

Investing in real estate: Investing in real estate offers more passive income cash potential - but more risk - than investing in stocks or bonds. You'll need substantial amounts of cash to invest in buying a home -- it usually takes 20% down to land a good home mortgage loan. But history shows that home prices usually rise over time, so buying home a for $200,000 and selling it for $250,000 over a five-year time period, for example, is a reasonable expectation when investing in real estate.

With $200,000 a year in passive income, I would have enough income to provide for a family of up to four in San Francisco, given we bought a modest home in 2014. Now that we have a son, I'm happy to say that $200,000 indeed does seem like enough, especially if we can win the public-school lottery to avoid paying $20,000 to $50,000 a year in private-school tuition.
This has become a popular business model for online entrepreneurs over the past several years, and will probably just continue to grow in popularity. The best thing about selling online courses is that once you do the up-front work in creating the course and setting up your marketing strategy, you can get paid over and over again for work you do once.