I started teaching Italian on Preply 2 years ago and it has been a good way to find students that I wouldn't have been able to get on my own.
Now I teach Italian to an Argentinian based in Buenos Aires and to some Spaniards based both in Madrid and Sevilla. I love the fact that I can set my own price and choose when I can teach.
I'd definitely suggest Preply and online teaching, but teachers please pay attention to the first lesson: the platform charges 100% of the first lesson, so make sure to generate engagement and loyalty with your student and you will gain money with time. The more you teach to a student the lower the %. Lastly, I also suggest participating to some of their free webinars arranged for tutors to get the most out of the platform.