One of the most common ways to make money while in USA on F1 visa is by working as intern (full time/ part time) as you fimd comfortable. This will help you make money and get real time practical experience both at the same time.
Another method applies if you have good online working skills, it could be anything from technical to social. Their are websites like fiverr, completely safe and genuine and it would help you make a lot of money if you are really good at something.
In order to use this website all you need to do is to create your profile and make sure it looks attractive, so that people wil attracted towards it and then you can provide your services to them. If that service requires core technical knowledge , believe me , you can make tons of money from this website.