In the document being finalized the following steps should be taken as appropriate or as you decide with only the three asterisk marked items actually being essential:
Do a final careful proofread correcting as needed. If you don't do it now you will likely have to update two documents in parallel later.
*Open the document in its native standalone creation program such as Word, Excel, or PowerPoint. Do not try to do these steps in the Online version.
*First Check Accessibility (in Word Ribbon: "File" > "Info" > "Check for Issues" > "Check Accessibility" then fix any issues as needed and run the accessibility checker again.) Be aware that the checking may turn up "issues" that need not be fixed but it will miss the many possible issues that cannot be checked by automated tools, e.g., are the headings meaningful or is the alt text on images appropriate.
Decide whether to keep the the current version of the document, perhaps with comments or change tracking intact, before cleaning it for posting. If you want to keep the current version intact then "File" > "Save As" under a new name then do the following steps to the copy rather than the original.
Accept All Changes (in Word Ribbon: "Review" > "Accept" [in "Changes" group] > "All Markup" [dropdown] > "Accept All Changes"). Save.
Delete All Comments in Document (in Word Ribbon: "Review" > "Delete " [dropdown, below "Delete" in "Comments" group] > "Delete All Comments in Document"). Save.
Optionally, if there is a "Title" property in the document, copy it to a safe place so you can restore it later. (in Word Ribbon: "File" > "Info" > under "Properties" then "Title:" field)
Optionally Delete All Document Properties and Personal Information ("File" > "Info" > "Check for Issues" > "Inspect Document" > [Yes if prompted to save] > Generally leave everything checked then "Inspect" then "Remove All" for items as appropriate to your needs, generally do NOT remove "Comments, Revisions, and Versions" but do "Remove All" "Document Properties and Personal Information". If you're not sure about something, "Close" the "Document Investigator" window and investigate and/or fix. > When satisfied with a final "Reinspect" "Close" the "Document Investigator" window.) Save.
*Fill in or Correct the Title Property ("File" > "Info" > "Properties" then "Title:" field [or "Properties" dropdown > "Advanced Properties" > "Summary" then "Title:" field then "OK"] Complete other fields as appropriate, perhaps "Author:"). Save.
Check for and manually remove stuck comments, etc., that the cleanup steps above didn't handle completely. Save. It is possible that an original copy of the document may be found to need correction also in this step.
A final proofread is also recommended, the catch being that if you're fixing a copy that is being prepped for final with the intent to work from an earlier pre-cleaning version, anything corrected here, should also be corrected in the pre-cleaning version. Save (both documents?).
Mark as Final the cleaned file (in Word Ribbon: "File" > "Info" > "Protect Document" > "Mark as Final").
Save the document and post or upload it to wherever is appropriate.