The world of freelancing can be a lucrative one. But it can also be wrought with scammers. Before you jump on 'the next big thing,' do your research to make sure the company and offer is legit.
There are thousands upon thousands of gigs out there for freelance writers. Always proceed with caution when choosing which gigs to go with and which contracts to sign. Only give the amount of info needed to receive payment. I recommend using PayPal for all transactions and invoices. This way, there is no need for you to give out bank information and certain other info that scammers can use. It also puts all transactions and agreements on record, especially if you send out the invoice outlining the agreement before the work is completed.
You cannot prevent every single instance of someone trying to con you. But when you proceed with caution, it does make being scammed less likely.