It's easy for millionaires to find passive income strategies that turn a profit, from commercial real estate investing to angel investing in a hot new technology startup. But what about the rest of us--those of us who want to create a system that lines our wallets without a ton of work?

It's entirely possible to earn a few hundred--or even a few thousand--each month with passive income. Normally, a ton of work upfront is required to get your system up and running and ready to start turning a profit. But fortunately, there are plenty of ways to get started with no or low investment. Here are 10 passive income strategies to try.

1. Rent Anything

Renting out something you own takes little upfront work and can yield a stable monthly income. One of the most popular ways to do this is to rent out a spare room--or your entire home--on Airbnb. But there are plenty of other things around your house or apartment that you can rent.

For instance, rent out your bicycle for the weekend through SpinLister--you choose when it's available for pickup and drop-off. Or, even though you may only see about $30 from your effort, sites like Just Park can turn your driveway into a passive income machine. Rent it out for a sporting event or to a nearby apartment dweller who needs space for her car.

2. Invest in Unique Real Estate

Renting out a house to monthly tenants can turn a profit, but it can cost hundreds of dollars once you take into consideration maintenance, property management fees, and the mortgage.

While it's not a bad place to start, you can up your game and crowdsource real estate investing. Spend just $5,000 with a site like RealtyMogul.com (as long as you meet the site's participation criteria), and start investing in properties while someone else deals with all of the hassles, from sanitation to upkeep. It's also one of the few ways to invest in commercial real estate rentals without needing to be a multimillionaire.

3. Launch a Microbusiness and Outsource It

Entrepreneurs often suffer from dreaming up too many ideas with too little time to execute. Do some hustling to get that simple, straightforward, and irresistible-to-customers microbusiness off the ground. This could be anything from content marketing for startups to developing simple websites for dentists' offices.

Once you've got the details ironed out and a few clients lined up, outsource everything, from project management to writing, on a site such as UpWork. The idea is to find reliable virtual employees who can take over the running of the business for you, so you can check in once in a while and spend the rest of the time building your next business.

4. License an Idea

You don't have to be a product guru to license an idea to a company. Although the process to create a passive income this way is a long one, it can pay off big. Stephen Key suggests taking products to equipment manufacturers and seminars to get them into the hands of companies like Coca-Cola.

Or you could go the creative route and sell your idea to a reality TV producer or network. Sites like Virtual Pitchfest can put your pitch directly in the hands of decision makers and you are guaranteed a response. While some networks may want a fully-formed idea with talent attached, others are just looking for fresh, new concepts, and are willing to pay for them. They may even give you a development credit.

5. Start a Subscription Business

It's true that a subscription business takes some upfront hustle and hard work to get off the ground, but execute it correctly, and you could sit back and watch it run itself.

Once you've identified your concept and product, hire a fulfillment house to package and send out your subscription boxes or products for you. Cratejoy can also handle the logistics of signing on new customers and managing the process, so you're not stuck combing through your inbox in the midnight hours.

6. Become a Silent Partner

You don't need millions to become an angel investor when you can become a silent partner to a growing company right now. Silent partners invest money in an enterprise and can see a healthy return on their investment without doing much once the set up is complete.

Taking on the role of a silent investor takes some serious research into the company, their product or service, and their existing leadership. But once you're comfortable with the potential of a startup, investing your money can turn into easy passive income. The upside is you don't have the stress of putting in long hours for the company, and you have the freedom to build up a thriving portfolio.

7. Create CD Ladders

Investing in stocks and bonds is a common way to build passive income, but it isn't always a safe bet for amateur investors. It's one thing to use a financial adviser to invest in your retirement and future, but it's another to try to build passive income through investments on your own. Instead, consider CD ladders.

Despite low interest rates, CD ladders can help save money and ensure a safe return on your investment. The strategy involves dividing the amount of money to be invested into equal amounts to CDs with different maturity dates. This can ramp up your return for more interest income.

8. Package Your Expertise

It's easy to dismiss your expertise as something no one would pay for, but that is rarely true. Book a free speaking event at a seminar or conference on anything from small-business bookkeeping to running a remote team. Ask your audience to sign up for your newsletter and sell your video series, print-on-demand resource book, or product to interested parties.

While this idea isn't entirely passive, the potential to develop a product and sell it to hundreds or thousands of people at once will put money in your pocket without requiring that you create a new product for every sale.

9. Repurpose Your Work

What's lying around in your online storage? Business templates, sample contracts, PowerPoint presentations, and audio notes can all be repurposed and sold multiple times. Start big, like selling a complete series of helpful business resources to your clients, all the way down to Kindle books and membership sites that offer ongoing resources to paid members.

10. Sell Digital Artwork

There are more options for selling digital artwork than just stock photos and WordPress templates. There are hundreds of users on sites like Etsy selling digital downloads of website buttons, graphics, illustrations, and wallpapers over and over again for a profit.

The internet is rife with stories of people selling photos on social-media sites, sometimes with help from companies like Candidly that help connect Instagram photographers with companies looking for candid photos to purchase for advertising campaigns.

Got another passive income earning idea to add to this list? Let me know by leaving a comment below.