Yes, it would be nice if you could just type up one page of items to sell or join one website that just printed you cash every day of the week for the rest of your life. But even overnight successes are never really overnight successes. They have usually worked hard to get to be that successful. It just happens that they made their break happen for them.
When you engage in creating multiple streams of income you are hedging your chances of success and increasing the ways in which you can make that break from the life you have to the life that you want.
The thing about this line of making multiple streams of income work is that you can do what you love. You therefore do things that you might do anyway and so there is an added reward, the things you love to do may end up being a cash earner for you.
So for instance, if you like making jewelery. You might just make it for yourself, for fun or as a gift for friends and relatives. Maybe consider selling one or two items that you have made on eBay or Etsy.
Who wouldn't love to own a unique piece of hand crafted jewelery?
But to create that item of jewelery takes time and effort and once sold you have to create another item.
You may like to write, you may write an article and post it to a website which pays you residual income from views. Websites such as HubPages or Yahoo! Voices are such examples. But in order to earn good residual income you need many articles. For instance Yahoo! Voices pay you just $1.50 for 1,000 views of all your articles. If you write one article you may get 1,000 views in a day if it is an exclusive and hot topic but they don't last long. It is much easier to write 1,000 articles or more (one articleper day of 300-400 words over three years will give you over 1,100 articles.)) But again see you need to invest time and effort.
The good thing about all this time and effort is that as you work at your chosen income streams you will get better and better. You'll invest less time and effort per item. You will get to the stage where it seems no effort at all.
Remember though. It takes time.