Steps
The order saves doing it twice
The thing most often repeated for no reason is numbering: it gets added, then a page is deleted, and the numbers are wrong.
First: merge
If the document is made of several files, merge first. Any correction before that will have to be repeated after.
Second: delete and rotate
Surplus pages and wrong orientations are fixed on the complete document, not on its parts.
Third: number and mark
Numbering and the watermark come last. That way the numbers match the document that will actually arrive.
The tools in that same order
- Merge the files into one document
- Delete the surplus pages and rotate the upside-down ones
- Extract what only one party needs
- Add numbering and any watermark as the final step