Sell old items.
One of the quickest ways to make money fast is by selling your old books, CDs (yes, people still buy them) and DVDs as well as smartphones, smartphone chargers and gaming consoles.
Some good places to sell your items are the usual suspects: Amazon.com, Craigslist or eBay. You can also try used electronics online marketplaces, such as Gazelle or Swappa. These online markets sell phone brands across the board, and at Swappa, you can sell your gaming console, laptop, smartwatch and tablet, as well.
Sell unique crafts.
Maybe you make beautiful hand-sketched greeting cards or can knit a mean baby beanie. Or perhaps you make doggy Halloween costumes or sweaters. You can sell your uniquely designed crafts on online marketplaces such as Etsy, Zazzle, CafePress or Threadless.
Sell something valuable, such as jewelry or a watch.
It isn’t easy to part with something that has market and sentimental value. However, it’s good to know that you have that option. Keep in mind, your jewelry or watch won’t fetch what you or someone else paid for it, but it is still good to get your item or items appraised if you have the time.
You can sell your watch or jewelry at local jewelers, pawn shops (the quickest), online marketplaces (Ebay or I Do Now I Don’t) or at the local coin shop or metal buyer. Or simply call to ask your local jewelry store if they can refer you to some places that buy what you’re looking to sell.
Sell your time and expertise online.
Amazon's Mechanical Turk (also known as M Turk) is a micro-task website, and the mechanical gigs on this site don’t require much skill, pay little -- less than a nickel -- and only take seconds. Earning money is a numbers game in this case.
Fiverr, TaskRabbit and Amazon Home Services all pay more per gig. On Fiverr, you can sell a range of creative services, such as editing or designing a new logo, whereas TaskRabbit gigs are more focused on mundane tasks, such as packing and moving and furniture assembly. Amazon Home Services, which launched in 2015, allows you to sell home improvement services, such as furniture assembly, house cleaning and handyman repair.
The freelance professional gig market Upwork is where skilled professionals build profiles and sell their services, such as web content writing, social media marketing and virtual assistance. After you create your profile, you can bid on posted jobs or wait for clients to come to you.
If you already have a specialty skill, such as plumbing, veterinary medicine or property law, you could make some quick and serious side cash by selling your expertise on already existing consulting and coaching platforms, such as Clarity.fm, where experts get paid by the minute to talk to clients over the phone or online.
Or sell your expertise on JustAnswer, where potential clients post questions online and registered experts (e.g. doctors, lawyers, antique appraisers, engineers, essay experts and many more) bid to answer the question.
Do some market testing and research.
Companies want to know your opinion, and they’ll pay for it. There’s a variety of ways for you to participate in market testing and research, such as:
UserTesting.com: You provide feedback on apps and websites for up to $10 a completed test.
Become a mystery shopper: You get paid to secretly visit stores and report back your experience. Find out more through these mystery shopper companies: Market Force, Best Mark, Sinclair Customer Metrics, Experience Exchange.
Join a research study or focus group: Companies will pay you to sit in groups and answer consumer questions. You can sign up for focus groups at SIS International, Focus Group and Global Strategy Group.
Fill out online surveys: Register your information for a market research survey site, and you’ll be contacted when there is a survey that fits your demographic. Here are some survey websites where you can register: MyPoints, Survey Junkie, Pinecone, Survey Spot and Opinion Outpost.
Join the ride sharing economy
To become a driver, you’ll need a car in presentable working condition, a clean driving record, driver’s license and the proper authorization to work in the city where you want to drive. The driver’s background check takes five to seven days, according to Uber.
Drive for the on-demand food economy.
If you decide to sign up as a driver for the on-demand food economy, you’ll need a car and a clean driving record. For Postmates, an on-demand food delivery service, you’ll get paid approximately $20 an hour -- not including tips. If you drive for Uber EATS, you’ll deliver food from local restaurants in participating cities, and like with Postmates, you can earn $20 an hour. Both Postmates and Uber EATS have an in-app tipping feature.
Walk dogs or cat sit.
If you choose to make some money walking dogs, you have options: You can join a dog walking service specific to your area -- or cut out the middleman entirely and hit up the local dog run to hand out flyers and business cards to dog owners and leave business cards and flyers in pet stores.
Also, there is a bustling scene of dog walking platforms that connect dog walkers to dog owners, such as Rover, Wag and Bark. They all operate similarly. You, the dog walker, create a profile and wait for clients to contact you. Or you can bid on any jobs you see. (Make sure you build an online reputation of excellent reviews, which helps you get more jobs down the road.)
In the same vein, you can also cat sit. You can list yourself as a cat sitter or pet care provider on a peer-to-peer online marketplace such as Thumbtack, or sign up as a sitter at a local pet care business.
Become a tutor.
Tutoring is flexible. You can work on the weekends and evenings, and tutors in certain subject areas are in high demand. You can earn upwards of $50 an hour tutoring physics, math and science, depending on your experience and where in the country you tutor. (On average, tutors earn $17.28 an hour, according to PayScale.)
You can apply to be a tutor with companies such as Kaplan and Kumon, however, many tutoring companies are regional and cater to the area. Also, you can use a tutoring marketplace platform, such as Wyzant, to create a tutor profile and bid for tutoring jobs in your area or wait for client requests.
Another rising trend is virtual tutoring in English to school children who live abroad, which gives you the flexibility to work from home, at sometimes, odd hours, due to the time difference. Some companies to check out are VIPKID, Englishunt, Topic-Time, Twosigmas, Lingoda and Funbulous.
Related: How to Make Money With Social Media
Work for a caterer.
You can join a catering company to make some side cash as a server or wait staff. It’s a flexible position, and catering companies often allow you to determine your availability. (No wonder struggling artists who need to be available for auditions often turn to catering.) You can also register as catering staff for a hospitality and events staffing agency in your area, such as Waitron.
Donate sperm or eggs.
To donate sperm or eggs, generally you have to be young -- over the legal age of 18 and typically under the age of 35. Donating sperm to your local sperm bank or fertility clinic program can yield a man anywhere from $30 to $200 per donation.
Egg donation pays significantly more. Typically, donation payments range from $5,000 to $10,000. However, the egg donation procedure is far more invasive and time-consuming than sperm donation. Typically, each donation requires a woman commit around four week to take fertility drugs, undergo egg retrieval and recover from surgery.
Babysitting is a job you can start doing immediately. There’s a high demand for babysitting and childcare services, whether it’s regularly picking up and dropping off children at school for two-parent working families or accompanying a family on a trip as a childcare provider.
You can offer your childcare services via word of mouth and leverage your social media and personal networks to market yourself. Or you can use online marketplaces such as Care.com, Urbansitter.com and Sittercity.com that connect childcare professionals with jobs.
Become a "landlord" in the sharing economy.
Work as a handyman.
If you can do basic home repairs -- installations, repairs, light painting and caulking -- you can square away some cash being a handyman. Whether your home repairs skillset is limited or sophisticated, just be upfront about what you can do well. Building a handyman business is reliant on good word of mouth.
To generate business, you can go the analog route and leave flyers and cards in the common areas of apartment complexes or hardware stores in your area. (And leverage your social media connections.)
Provide moving or hauling services.
This work is for someone who is physically robust and looking to make some extra bucks. (People who hire movers and haulers usually tip.) Be ready to work on weekends, when the majority of moving and hauling takes place.
To get into this line of work, you can join a moving and hauling service in your area, or if you have a van or a truck, you can go independent and advertise moving and hauling services on your own, which is how the company Man with a Van started out.