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.
The main idea behind the new passive income rules is to create a system that taxes businesses proportionally to their overall size and income amount. If you’re mostly dealing with smaller startups and family-run businesses, these new passive income rules will probably have little effect, and may even allow companies more freedom to grow their business.

During 2017, John was unmarried and wasn’t a real estate professional. For 2017, he had $120,000 in salary and a $31,000 loss from his rental real estate activities in which he actively participated. His modified adjusted gross income is $120,000. When he files his 2017 return, he can deduct only $15,000 of his passive activity loss. He must carry over the remaining $16,000 passive activity loss to 2018. He figures his deduction and carryover as follows.
Generally, rental activities are passive activities even if you materially participated in them. However, if you qualified as a real estate professional, rental real estate activities in which you materially participated aren’t passive activities. For this purpose, each interest you have in a rental real estate activity is a separate activity, unless you choose to treat all interests in rental real estate activities as one activity. See the Instructions for Schedule E (Form 1040), Supplemental Income and Loss, for information about making this choice.

1. Interest: If the interest a landlord pays on their mortgage isn’t their biggest expense, it is certainly close to it. Even with rates as low as they are today, interest payments are a sizable cost that needs to be accounted for. Nonetheless, for as intimidating as interest payments can be, they are not without their benefits. Mortgage interest has become synonymous with one of the largest deductions landlords can make. Passive income investors can deduct mortgage interest payments on loans used to acquire or improve a rental property. However, it is important to note that they can also deduct the interest paid on credit cards specifically used to to maintain rental property activity.
Of course, a book isn’t the only way to get your thoughts to the world nowadays. You could also start a blog, website or YouTube channel to earn some passive income. Besides the creation of your website, videos and content, blurting out your ideas and advice online seems pretty passive. However, it will take a lot of work on your part and time to gain readers, followers and then paid advertisers. You will need to make your content marketable and appealing. That way you continue to gain followers, advertisers and money.
If you are going to take the after-tax business income out of the company in the year it’s earned, then you’re not enjoying any tax deferral and the loss of the SBD is likely immaterial. If, on the other hand, the after-tax corporate income is retained in the corporation and not paid out as a dividend until a future year, then losing the deferral available on SBD income could be material.
Another benefit of investing in rental properties is the loan pay down. If you obtain a loan to buy the property, each month your tenants are paying off part of the loan. Once the mortgage on the property has been paid off, your cash flow will increase dramatically, allowing your mediocre investment to skyrocket into a full-fledged retirement program.
If you know anything well, a place, how to fix something, how to make something, how to do something, you can write a guide for it. You can sell your guide as an e-book, offer it as a download for a fee on your site or reach out to bloggers with similar content and ask if they will offer it as a paid download on their website (for a price of course).
I have only dabbled in drop-shipping before when I had an eCommerce platform 6 years ago or so. I think it is something that you could do on the side, but you would want to do in depth research on the industry you want to get into before setting up shop. It may be a little less passive up front, but over time you could take your hands off the wheel.