Another way to generate passive income is to invest and be a silent partner in a business. This is very risky, but with risk comes the potential for high returns. For example, several years ago both Lyft and Uber were looking for private investors to invest in their companies. Today, they are worth billions - but you as an investor would only reap that benefit if they go public via an IPO, or get acquired. So, it's risky.
2. Treat Passive Income like a game, cheating is using your spouses income in this game. I understand some of the premise behind this, but I’m married, my wife has an income and we have a rental house that we consider ours. I’m not sure how I would count this since we also use another part of our own home(also rental income) to pay down the Rental house.
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.