I would throw in some caution here: if your spouse works at the same company, or in the same industry as you, you are not diversified, and should something happen, you could be in a world of hurt.  Companies do go out of business, companies do lay employees off.  There is nothing wrong with working together, but realize that you are not diversified and you should be trying to maximize other income streams as a result.
Following the success of the bestselling Multiple Streams ofIncome, Multiple Streams of Internet Income took theidea of making money on the Internet to the next level, byrevealing how to deliver a marketing message faster, cheaper, andto a larger number of potential customers. This new updated editionincludes the same wisdom that made Allen one of the mostinfluential financial advisors in the world, but also featuresupdated information on everything readers need to know.
Add Leverage (Mortgage) and you greatly increase the ROI especially from the perspective of using Rents (other peoples money) to pay down the mortgage and increase your equity in the property over time. At this point then yes price appreciation is secondary bonus and we have an arguement of how and why Real Estate can be better than Growth Stocks in some scenarios and for some investors.
Create a Course on Udemy – Udemy is an online platform that lets its user take video courses on a wide array of subjects. Instead of being a consumer on Udemy you can instead be a producer, create your own video course, and allow users to purchase it. This is a fantastic option if you are highly knowledgeable in a specific subject matter. This can also be a great way to turn traditional tutoring into a passive income stream!