If you have an extra room in your house, consider listing it on Airbnb. Airbnb is a new way to travel for many people around the world. Instead of booking through expensive hotels, why not stay at someone's house? As a guest, you can choose high end to low end, choose to stay with other people or opt for privacy. As a host, it's a great way to make side money, utilize unused space, and meet new people! How much you can earn depends on your area so I recommend finding out by becoming an Airbnb host yourself!
 @dasjung No doubt! I know this and you know this, and any other highly skilled and educated designer will also know this. But what about the customers? The people who are looking for a logo design with much consideration of price in this economy.  Knowledge and talent expect the monetary reimbursement it deserves, but unless everybody has a trained eye to recognize it, they just aren’t going to dish out the money for it. That is the point I am trying to make. It is like calling the neighborhood handyman instead of  a high cost plumber to fix a small leak.
As I’ve thought more deeply about how to answer this question over the years, I’ve come to a realization that the problem is not the answer, but the question itself. For those who’ve asked it, I don’t think it’s always coming from a place of “quick money.” If we reframe the question, I think there’s room to empower and actually help those who’ve asked it—to give them a foundational understanding of what it really means to generate an income online.
Learn then selling guidelines. Each marketplace has guidelines that define what you can and cannot sell. State and federal laws also impact what items are prohibited. In general, you cannot sell alcohol, weapons, service contracts, animals or event tickets. Also, while not always prohibited, you may find restrictions on how you can sell items in some categories, such as art, gift cards and coupons.[27] eBay, Craigslist and Amazon publish these guidelines on their websites.
While I think that your initial response to Phillip’s suggestion about design was a little too strong, Dasjung, I’ve got to chime in here and observe that Phil, ThunderCock and Dumbass, by resorting to name calling and simplistic reasoning, come across as very lacking in both decorum and sensitivity.  If a guy wants to expect, even demand, high quality in his field of choice, I beleive he has a right, if not a responsibility, to do so!  Also, Dumbass, be careful who you call Dumbass. You just show YOUR true colors by doing so. 
If you want to clear some space out in your house and have a big stack of books you’ve been holding onto for too long, you can make money selling your books and textbooks online. Stores like Half Priced Books and others will give you cents on the dollar for each of your current books while you can check what your book is worth by simply entering the ISBN number on Book Scouter.
Tutor students. If you have an academic specialty and can squeeze in a couple of hours during the week while Junior is taking a nap or Janie is at gymnastics, share your knowledge with struggling students. Find students looking to improve their grades on your own through your kids' schools – check a site such as Craigslist.org to gauge hourly rates in your area – or sign on with an online tutoring company, such as Tutor.com. You must be available to tutor at least five hours a week and have a college degree to tutor certain subjects for Tutor.com. Tutoring is done virtually from home via a computer, not in person. Tutor.com tutors are paid an hourly rate based on the subject.
There was a time when CDs would produce a respectable 4%+ yield. Nowadays, you’ll be lucky to find a 5-7 year CD that provides anything above 2.5% The great thing about CDs is that there are no income or net worth minimums to invest, unlike many alternative investments, which require investors to be accredited. Anybody can go to their local bank and open up a CD of their desired duration. Furthermore, a CD is FDIC insured for up to $250,000 per individual, and $500,000 per joint account.
Making some extra side hustle cash doesn't actually have to be that complicated. As someone who's been immersed in the field of online income generation for nearly two decades now, I can tell you that it takes some work. However, there are several clear paths forward. At the end of the day, it all boils down to what your goals are and just how much you're looking to automate your income.
That $200,000 a year might sound like a lot to you, but the median home price in San Francisco is roughly $1.6 million or almost eight times our annual passive income. For a family of three in 2018, the Department of Housing and Urban Development declared that income of $105,700 or below was "low income." Therefore, I consider us firmly in the middle class.
In 2012, even I wrote a 150-page eBook about severance package negotiations that still regularly sells about ~35 copies a month at $85 each (2nd edition for 2017) without any effort. In order to generate $2,975 a month or $35,700 a year in passive income as I do now, I would need to invest $892,500 in something that generates a 4% yield! To earn $10,000 a year in passive income would therefore need roughly $250,000 in capital.
For those willing to take on the task of managing a property, real estate can be a powerful semi-passive income stream due to the combination of rental and principal value appreciation. But to generate passive income from real estate, you either have to rent out a room in your house, rent out your entire house and rent elsewhere (seems counterproductive), or buy a rental property. It’s important to realize that owning your primary residence means you are neutral the real estate market. Renting means you are short the real estate market, and only after buying two or more properties are you actually long real estate.

Multi-vendor marketplaces, like ThemeForest, can be very successful. Chose a niche and create a vendor website for it. Your marketplace could be anything, from a platform for local artists to sell their work on, to an online digital product store. Once set up, invite people in that industry to sell their products on your site. You take a percentage of their profits when items sell.
Cafe Press: This website allows you to create digital designs that can then be sold on the platform. You'll earn a commission for everything that sells and you'll never have to deal with logistics like printing, warehousing and customer service. If you have some graphic design skills, then this is a great potential source for your web-based income.