Active income requires your time and you can only produce as much money as your time allows. For example, a doctor or a lawyer who charge high per-hour or per-consultation fees and make exorbitant amounts of cash are stifled by the amount of time they have in a day. We all have the same 24 hours. Not one person on this earth gets more time than the next. It’s the greatest equalizer in life. When the time you work directly correlates to your income, it’s called active income.
But don't make the mistake of thinking this will be a passive source of income—you're on call whenever you have a guest and you'll always need to keep the place clean for incoming visitors. On top of just renting on Airbnb, consider offering your guests paid add-ons, like Lauren Gheysens', Royal Day Out in London, England—where she gives visitors a local's only tour of the city, complete with bespoke 18th century costumes.
It comes down to knowing your market and its potential before you get started. If you don’t know what is possible, or overestimate the actual return, you can spend years learning how wrong your early decisions were. That’s because you will have some encouraging success early on only to wake up later and realize it’s not what you want, and that you aren’t going to get there without painful and expensive (in time and money) changes. Changes, that with good, deep research, could have been avoided.
Using Fiverr is a great way to pick up work. Once you have signed up you can advertise your services. Fiver allows you to create your own gigs, whether you are offering web design, digital marketing, writing, or something else. You can choose how much you want to charge (it can be more than a fiver) and people will then contact you if they are interested in working with you. Fiverr will not only help you get experience if you are just starting off as a freelancer, it will also help you earn some extra cash.