My e-product is currently in development, but I think it could reasonably bring in 1/25 of my income in the first year with minimal promotional effort. If it takes off, maybe 1/5 of my income. Building that up so that I could direct all the proceeds to paying down student loans is a great incentive. I need to focus there, but I also have a few other non-traditional digital products in mind. I need to test the market there before expending too much time or energy.

Finally, make sure you can service multiple types of clients. This is the best egg to have. Even for something as simple as a dog walking business, you can service multiple types of clients. For example, you can offer a puppy walking service and an adult walking service. You can have weekends at the park services. You can offer to take the dog to the groomers. Try to meet client’s individual needs.

If retirement is a goal of yours (and who doesn’t want to retire someday?!?), it’s important to learn how to start investing. In fact, funding your retirement accounts should be at the top of your list. While these accounts won’t help your immediate situation, by stashing cash now, the residual income they create should help propel you through your golden years.
The legendary investor, Warren Buffett rightly said that if you cannot create a second source of income by the age of 45, then you have really done injustice to yourself. If you are in business or if you are an independent consultant there are multiple streams that you can consider. But what if you are employed and your existing contract does not allow you to take up other work? Also, your pressures at your workplace may be tight enough to leave you with little spare time to worry about how to create a second stream of income. That is when you have to make money work hard for you. Let us look at two such approaches.
Taking Paid Surveys at Home: I was skeptical, at first, until my 17 year old son starting making money at home taking paid surveys. Companies desperately want your opinion, and they are willing to pay for it. The trick, of course, is knowing where to find the paid surveys that pay the best. One of the most popular and legitimate survey sites is Swagbucks. Not only can you make money taking surveys, but you can also make money by watching videos and even surfing the net. They also offer significant cash back for online shopping.
Ebooks are one of my favorite sources of passive income. Now, you can do this the simple way and just publish it on Amazon's KDP. Or, you can go all out and build yourself a book funnel. Book funnels are powerful, but they won't be fully passive. For example, if you do a free-plus-shipping offer for your ebook (converting it into a physical book), you'll need to create some one-time offers (i.e. extra training) and up-sells (i.e. an audiobook). But, a book funnel can be very powerful.
Peer-to-peer lending means loaning money to other people. Specifically, you lend money to people who don’t qualify for traditional financing. Companies like Lending Club and Prosper offer returns in the range of 4-10%, which are a lot higher than a typical saving account. You will be able to select the right investment for you, based on your risk assessment strategy.
Not only that but in almost all other cases there is the illusion of influence, which is itself a psychological and emotional cost. If you invest in a business that your friend or family member is running, you can see how things can get messy. You have thoughts on how things should be done, they have competing thoughts, if things aren't going well… we know how this story goes.
Real Estate Income – Since we moved up to Newport Beach, I started renting out my condo in San Diego. My monthly cash on cash return is $300(I charge $1,900 for rent and my total payments including mortgage, HOA, property tax and insurance are $1,600) but I also get back around $350 every month in principal and about a $150 tax savings per month. But even this income is inconsistent, since sometimes expenses will pop up like last month when I had to buy a new A/C for $3,000!

I knew I didn’t want to work 70 hours a week in finance forever. My body was breaking down and I was constantly stressed. As a result, I started saving every other paycheck and 100% of my bonus since my first year out of college in 1999. By the time 2012 rolled around, I was earning enough passive income (~$78,000) to negotiate a severance and be free.

There is also an idea that we should work to build a passive income asset and then sit on the beach relaxing for the rest of our lives. The truth is that most people would get extremely bored with this scenario and will be eager to find something to do. That’s why the world’s billionaires continue to work… they love what they do and it stopped being about the money a long time ago.