Know the difference between an asset and a liability. The dividing line is whether it puts money in your pocket, or takes it out. As much as you love your home, for instance, it is a liability rather than an asset because you put more money into it than you get out of it (unless you're flipping it or renting it out). Whatever money you save, invest it in assets such as stocks, mutual funds, patents, copyrighted works--anything that generates interest or royalties. Eventually, you might get to the point where your assets are doing the work for you, and all you have to do is sit there and make money!
Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online.
Has anyone ever told you you have a voice for radio? Are you great at creating original characters with just your voice? There are tons of people looking to pay for quality voice overs for their corporate videos, animation series, or educational videos. Check out Fiverr and UpWork or create a profile on a specialized site like Voices.com or The Voice Realm to get started making money online doing voice overs.
Robert said he did an average of 4-6 of these gigs per year for a while depending on his schedule and the work involved. The best part is, he charged a flat rate that usually worked out to around $100 per hour. And remember, this was pay he was earning to advise people on the best ways to use social media tools like Facebook and Pinterest to grow their brands.