what are the best ways for freelance writers to avoid credit card / Paypal fraud?
You can ask the client to produce a non-official proof of ID to prove ownership of the card. A membership card or something that does not contain privacy law protected information should suffice. However, credit card companies always tell the users that the card with a signature is enough to validate the card. No additional ID is required. If you are worried about potential chargeback complaints, you should not worry about that as long as you provide everything you agreed to with the client.
someone has reversed Paypal transaction.
- That happens sometimes. However, there is a investigation conducted and you will be allowed to present your evidence to prove you fulfilled your end of the bargain with PayPal. Never assume that PP will automatically side with the client. If your evidence is strong enough, you can win and prevent the chargeback from being fulfilled.