​If you pay your bills with a credit card make sure it offers cash back rewards. You can let your rewards accrue for a while and possibly put the easy money you earned toward another passive income venture! (Be sure that the card you select doesn’t have an annual fee or you might be cancelling out your rewards). Check out this list of the best Cashback Rewards Cards.
Investing in a business: Another good way to generate passive income is to invest in a business --even a small one -- in return for a percentage of the profits - just like Shark Tank, only smaller. Lending $10,000 to a local business that, for example, is working on a mobile app for Apple phones could lead to a passive income-generated share of the profits when that mobile app starts selling like hot cakes.

First: I understand why you would say that such investments are restricted to only accredited investors, because generally, that’s true. There are means, under federal securities regulations and Blue Sky laws in each state, to sell interests to non-accredited investors – but usually those means are so heavily regulated and involve disclosures so similar to cumbersome registration requirements that it is not worth it for the seller to offer to non-accredited investors.
Large corporations often use a higher rate than the risk-free interest rate when calculating the residual value of individual departments or an entire firm. They often called this rate the required rate of return or minimum acceptable rate of return. There are various ways of calculating such a rate, but the main reason it is almost always higher than the rates offered by certificates of deposit is the higher risk involved in a business. After all, investing money in even the safest corporation involves some risk of never again seeing part or all of your money again, whereas a bank deposit is government guaranteed and virtually fail-proof. Therefore, businesses consider themselves to be adding economic value only if they can surpass a higher benchmark than the risk-free interest rate offered by banks.
In equity valuation, residual income represents an economic earnings stream and valuation method for estimating the intrinsic value of a company's common stock. The residual income valuation model values a company as the sum of book value and the present value of expected future residual income. Residual income attempts to measure economic profit, which is the profit remaining after the deduction of opportunity costs for all sources of capital.