When we took Skamp in for her final vet visit (congestive heart failure), we didn't get an opportunity to "just sign the paper" and leave.
One of the vets sat with us and went over the options (ways to keep her alive, costs involved) and then, once "the decision" had been confirmed, we had another discussion of options (disposal, burial, cremation, ashes->urn, etc.).
There was simply no opportunity to "just sign" and be done.