I am still working on my passive income, however I like multiple income streams even more. My favorite is capital gains because it is one of the lowest rates. One of the best passive income streams is a pension/Social Security. As I near retirement, I like the concept of it supporting my needs and my 401k supporting my wants. In addition, my brokerage accounts are all at capital gains rates. Don’t misunderstand, I am still working on adding more because I like multiple income streams!
One of the most appealing options, particularly for millennials, would be #12 on your list (create a Blog/Youtube channel). The videos can be about anything that interests you, from your daily makeup routine (with affiliate links to the products you use), recipes (what you eat each day) or as you mention, instructional videos (again with affiliate links to the products you use). Once you gain a large following and viewership, you can earn via Adsense on YouTube.
Investing in real estate: Investing in real estate offers more passive income cash potential - but more risk - than investing in stocks or bonds. You'll need substantial amounts of cash to invest in buying a home -- it usually takes 20% down to land a good home mortgage loan. But history shows that home prices usually rise over time, so buying home a for $200,000 and selling it for $250,000 over a five-year time period, for example, is a reasonable expectation when investing in real estate.
When you invest in a dividend-paying stock, you are buying a share of the company and you literally become part-owner of that business. As the company grows and generates extra cash that it doesn’t necessarily want to re-invest, it might decide to return some of the extra cash to the shareholders in the form of dividends. And because you own a fraction of the company, you will receive a portion of the cash!
If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.