REALLY DAMN IMPORTANT FOR ARTISTS TO READ!
Previously: Paypal and Commissions!
[EDIT] Some of Paypal's UI has been updated to the point that some of these screenshots will look unfamiliar when on Paypal's website. Despite the updates, the wording is exactly the same so don't freak out.
[EDIT2] As of September 2020 I am no longer active on deviantArt and will not be able to answer any questions. If you have any questions, please look in the comments for possible answers.
The last thing I wrote about receiving payments on Paypal was that both artists and commissioners HAD TO tell Paypal that their digital product had already "been shipped,"