In short: Approve first, then export the set.
Exporting is the last step, and the one where format matters. What you need depends on where the work is going.
1
Approve what you are taking
Export what has been reviewed, since it is easy to ship a draft otherwise.
2
Choose the right format
Different destinations want different things, and the export options reflect that rather than giving you one file to convert.
3
Take the copy as well as the visuals
The words matter as much as the layouts when someone else is scheduling the work.
If you have publishing integrations connected, you may not need to export at all.
