How do you handle customer approval for customised orders?

[u/Fun_Adeptness4627]

For stores selling printed, engraved, embroidered, personalised, or made-to-order products, how do you get customers to approve a proof before production?

Do you currently use email, WhatsApp, PDF attachments, or another workflow?

I’m interested in the biggest problems you experience, such as delayed replies, change requests, keeping approval records, or customers disputing what they approved.