Quick money also require work and effort. Well that in people minds perpetuates the image that there are no shortcuts. Especially when it comes to money which can not be easily and quickly earn unless you win on lottery. Even blogging is not so simple, you need a lot of time devote to writing content that will be valuable to users, positioning, etc.
If you're not self-employed and work for a company, find out if they have a retirement plan. If you're lucky, employers will sometimes match contributions you make into a retirement fund. Retirement plans also often have the benefit of being tax-deferred. The longer you get to keep your money (and make interest on it) the better. It's never too early to start planning for retirement.
Sell hair, plasma, or other body parts/fluids. Long, healthy, untreated hair can be sold for a variety of purposes (including high-end wig- and extension-making) and earn you anywhere from several hundred to several thousand dollars depending on color, health, and length. Plasma can be “donated” (for compensation) provided that you are old, healthy, and heavy enough to qualify. Sperm can be donated, but you usually have to know (and be able to document) a fair amount of information about your parents as well as your medical history to be eligible. But be wary; for example, donating eggs is often touted as a fast, high-profit medical procedure, but the process is actually requires that the participant undergo hormonal and medical treatment, receive regular checkups and ultrasounds, and abstain from sex and intoxicants, all of which take weeks or even months before the eggs are even eligible for removal. The removal process itself is invasive and lasts about 30 minutes. Consider your options very carefully before taking on anything like this.