Can you create a Packing Slip for the customer?
Enhance customer experience with Rich Commerce's packing slips. Learn how to create customized summaries of orders, including shipping and return details.
In the email templates you can use the dynamic variables {ITEM_DETAILS} as well as {RMA_NUMBER} and {ORDER_NUMBER}.
Make sure to include these in the email to your customers and then let them print out the email and add it to the items being returned.
Your warehouse staff then has all the details on the return.