Return Label/Slip

I am looking for advice on creating an additional template.
My customer would like to add a return slip/label to the despatched product. The return slip ideally would consist of:
*return instructions (printed on the separate piece of paper or as a tear-off element)
*label with:
* customer address as a sender ‘from:’
* company address as a recipient ‘to’:
* some details to identify the order
I am happy to change settings in the WordPress admin area, add shortcodes or create custom PHP code.
Please advise on the best approach to fulfil my customer request.

Kind Regards
Michael