Set up an approval task with one current proof, a decision question, and a due date.
Add a review subitem when a campaign proof is ready.
Your reviewers get a dated task for the current proof, with the decision they need to make before launch.
Identify the current package proof for its reviewer.
Your reviewers get a clear task for the current proof. They know what decision to make and when it is due.
Assign proof approvals agreed in production meetings to reviewers.
Your reviewers get a clear task for the proof decision, with the link and due date from the meeting action item.
Set submitted print proofs up for approval by the due date.
Your reviewers get a clear approval task on the submitted proof, with the decision to make and the date you requested.