Here are some guidelines for setting up your Word/ LibreOffice documents so they will be good for publishing. These notes apply equally to spreadsheets and presentations as to word processor documents.
Remember that a document should be published as a .pdf unless the document is meant to be edited by the recipient or used in its native format. This applies whether it is meeting notes, spreadsheets, even presentations.
Firstly we use the U.R.C. Visual Identity guidelines as our baseline.
Fonts
These suggest that we use Arial* as our usual font. Arial is a fairly plain Sans-serif font and it, or a closely matching font, is readily available on almost every device. A Sans-serif font is recommended over a Serif font (such as Time New Roman) as they are easier to read for people with reading difficulties.
The URC guidelines suggest these font sizes: Main title: 26pt bold, Heading 1: 16pt Bold, Heading 2: 14pt Bold and for the main body (Body copy/Normal) 12pt Arial with 1.15 spacing.
To achieve this you should edit the Paragraph Styles rather than applying the fonts to selected text. That way it will apply for the whole document. Here is a Youtube Video which shows how to go about this in your desktop version of Word (he is using word 2019, but I suspect it has not changed that much).
What he does not say is that the Paragraph Styles are hierarchical. The default paragraph style ('normal') is at the top of the tree, meaning every other style in the document inherits the settings of that style unless it is specifically overridden. So when he edits the 'normal' style it actually changes the font for every style he used in his document.
I recommend that you create a blank document, set the styles to suit, delete any content you have typed to test things, and save it as a template (.dotx). When you create a new document from a template you get an untitled document so you can't accidentally overwrite the template.
I have only access to the free version of 365 (at https://login.microsoftonline.com/) so the paid version may be different. On the free version, I opened an new 'Blank document'. Here I can type in some text - it is a 'Normal' style paragraph and the default font is Aptos*. Then I can select some text in that paragraph and modify it locally - say change the font, font size, font colour, whatever. Then clicking on the 'Styles icon' opens up a dialog showing the styles in a similar way to the 'Styles tab' in the video. Right clicking on the Normal style allows me to choose 'Update Normal to match selection'. This does what it says. I noticed that most other styles inherit the changed font, but not any 'Heading 1' (and similar) styles nor 'subtitle' style; These all need editing separately. This behaviour is set by the original document and/or it's template.
The trouble with fonts!
*Arial is a widely used Microsoft font. This is because in 1999 MS released the font with several others as a Core fonts for the web. Anyone could download and install these fonts for their own use (on their computer) without any fee. MS withdrew this agreement in 2002. Although the previously released zip files are still legally available, they contain an old (2000) version of the font. Arial is now deprecated by Microsoft.
*Aptos, (aka Bierstadt) is a sans-serif font introduced in 2023 as the new default font for Microsoft Office. It replaces the Calibri font. As a new MS font it is not legally available on a machine without windows or Microsoft Office, and neither is Calibri.
Most non Microsoft operating systems now offer equivalents which look similar to Arial, and take up almost exactly the same amount of space on the page. Some of these, such as Liberation Sans, are free and open source fonts, which can be used legally on any device. They can be set to replace Arial automatically if it is not available.
Out of interest the website uses a web family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "Noto Sans", "Liberation Sans", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"
(Noto and Liberation are open-source fonts, Arial and Segoe are Microsoft fonts, Roboto is the default Android Font, Helvetica was licensed to Apple, sans-serif is a 'font classification' meaning that if the browser can not find on your machine any of the other fonts in the list, it will use any 'sans serif' font you have.)
Page size, margins and language.
The URC guidelines suggest A4 page size. This is clearly something you should make sure is set correctly so that you can use the full area of the A4 page when editing.
They recommend 2.54cm (1inch) margins on all sides (top, bottom, left, right). Being a metric guy, and not wanting to waste paper I regularly use 2cm, or 1.5cm margins (especially on A5 sheets). However, for publishing, we should try to use a standard (Job for the communications group?).
Language
Also you should check that the default document language (proofing language) is set to English (U.K.) for the whole document, and for every paragraph so that we have British spelling and grammar checking. Most of the documents I have moved from the old site to the new had USA set as the default language for the whole document, and/or set as the language locally (per paragraph) in many, most or all of the paragraphs!
Paragraph spacing
I imagine that when you use Word for editing a document you are used to the Enter / Return key creating a new line in the document, and when you want space between paragraphs, you hit Enter twice?
It actually does not work like this - hitting Enter creates a new paragraph, but you can not tell because the space above and below the Normal paragraph is set to zero. This has been the default for MS for many years. It may be changing, because in my new 365 document the normal style was set to have a 0.28cm margin below the paragraph, and a 1.16 line spacing within. This is exactly how our website works. As on the website, in order to enter a new line within a paragraph you use Shift/Enter.
One advantage of setting a paragraph margin in the Paragraph Style is that you can change it globally in one place. Very often I receive a document which has just one line on the last page - very often the ''Yours faithfully' line. If you have used paragraph spacing you can just change the Spacing in the Paragraph Style by a small amount and it will bring the orphan line. up onto a page with other text!
So please make use of paragraph spacing - I set mine to default at 0.2cm below, and 1.15 line spacing within in my default template.