Writers Always Demand a Down Payment From Your Clients
There are lots of people on the net who will not pay freelancers for their work.On the net means virtually everywhere. You will find them even on sites such as freelancer and upwork.
To be on the safe side, each time you get hired, you should ask the client for a down payment. If you expect to be paid $300 for a project, ask for $30 upfront down payment. Then demand payment in installments (for the balance) as you work on the project so that by the time you are done, you should have been paid about 75% of the $300. This way even if the client doesn't pay the rest of the money owed, you at least won't lose everything.