A month later, the direct deposit hit my account. The next month brought another. I found myself greatly motivated to keep learning real estate, to understand what some of the terminology meant and the different ways to invest. Now that there was some money on the line, I became more interested than ever. Next thing you know, I had invested nearly $100,000 in total in various crowdfunding ventures.
* I use Personal Capital to track all my finances in one place. It’s much easier to use their free software to follow 28 accounts on one platform than to log into various accounts to check my balances. They’ve also got great tools for x-raying your portfolio for excessive fees, recommending a more optimized asset allocation, and planning for retirement with their Retirement Planner.
The second category of passive income is drawing on sources that do not require capital to start, maintain, and grow. These are far better choices for those who want to start out on their own and build a fortune from nothing. They include assets you can create, such as a book, song, patent, trademark, Internet site, recurring commissions, or businesses that earn nearly infinite returns on equity such as a drop-ship e-commerce retailer that has little or no money tied up in operations but still turns a profit.
While it is important to find something that you love to do and turn it into a money making business, you do have to be cognizant of the return as you pointed out. There are many opportunities that I found and tried out that at the time seemed great. But when I took a step back, I realized that I was working a lot for very little income whereas other things I love doing brought in much more money.
It’s a (mostly) short term, higher risk, higher reward place to invest cash that has a low correlation with the stock market, but is far more passive than buying and managing properties, has more opportunity for diversification than private placements (minimums of 5-10K, rather than 100K), and most of the equity offerings (and all of the debt offerings) provide monthly or quarterly incomes. Unlike a REIT, you can choose exactly which projects you wish to invest in.
Courses are similar to guides but they’re easier to produce for some subjects, especially tech subjects. If you’ve got a computer, a decent microphone and some screen recording software, it’s pretty easy to create high quality courses. You can sell your course through your own site or you can use a marketplace like Udemy to do all the heavy lifting. 
Another great way to get started is to identify an area of interest you have. For instance, Robert Duff has been successful in building passive income by selling books on Amazon. Then, go out and start talking to people. Ask them, “What are you struggling with right now? What are your biggest pains? What’s something you wish existed that doesn’t?” That’ll give you some ideas about where to get started.
P.S. I also fail to understand your fascination with real estate. Granted we’ve had some impressive spikes along the way, especially with once in a life time bubble we just went through. But over the long term (see Case Shiller real estate chart for last 100 years ) real estate tends to just track inflation. Why would you sacrifice stock market returns for a vehicle that historically hasn’t shown a real return?
So many great tips in this big post, thanks! I think it’s so true that people should focus on the things they do well at and are interested in. And yes save, save, save in the beginning and throughout. I have several interest and dividend earning investments and am looking to expand further. Diversification is a great goal for all of us so we can avoid having all our eggs in one basket.
If you’ve ever thought to yourself, “I wish there was a product that did this,” then invent it! Create a product, medical or otherwise, and sell it as a company or get royalties for it. It’s not impossible to figure out, I have many friends who have taken a concept to market. Don’t overlook an invention as a fantastic means of attaining passive income.