- A job. This is often the only source of income many people have but most jobs are not nearly as secure and sure as people think. What would happen if you go in to work tomorrow and the doors are locked, there is a note on the door saying that the company is out of business, and you won't even be getting a final pay check? While everyone should have the skills to get a job, and if you are so inclined you can make this your main source of income, but you should also look towards other sources of income as well just as a back up.
- Owning a business. Back in the day (way back) nearly every kid started out their work life as a small business owner. Whether it was mowing yards, having a paper route, or babysitting, kids had to learn all about being a good business person (showing up on time, charging competitive rates, advertising, etc). Unfortunately this seems to be a lost art for kids these days but everyone should be able to cobble together a small, money-making business for a bit of side income.
- Investment income. Why not let your money work for you, even while you are sleeping? You can do this with a little bit of money and a sound investment strategy. Whether you want to try your hand at investments (choose a good mutual fund over individual stocks to get started) or owning rental property (much more complicated than most people think), by investing your money, you can rake in the dividends without having to do much work at all.
- Royalties. Another way to work once and reap the rewards long after is to do something that creates royalties. Writing a book, acting in a film, singing a song, all of these are ways to get paid, repeatedly, from your work.
- Reselling. Wednesday is senior day at the Goodwill in Las Vegas. Occasionally, like today, the spouse and I will be at the Goodwill when it opens on Wednesday morning in the hopes of finding some good, half-priced deals. There is a small army of seniors--and others--however, who take this Wednesday morning ritual a whole lot more seriously than we do. Many appear to be resellers. They find good deals, whether at the Goodwill, at garage sales, or on Craigslist, then clean up the items and re-list them for sale, making a bit of profit in the deal.
- Online income. There are a number of ways to make income without even leaving your house. From low-paying Mechanical Turk jobs to more lucrative deals (freelance writing, freelance website design) many people can eek out a living from online income only.
- Providing skills. Even if you don't have a formal business set up, by refining and selling or trading your skills (everything from cutting hair to plumbing to fixing the neighbor's car) you can earn some extra cash and help others in the bargain.
- Renting your stuff. Do you have a spare bedroom? Do you have a car? Do you have a parking space in a densely packed city that you don't need? Chances are that if you aren't using these things 24/7 someone would like to rent them from you thus allowing you to make extra cash from something you weren't using anyway.
These are just a few ways that you can create multiple sources of income so you are never at the mercy of one employer or one paycheck coming in each month.