I was asked by a client how she could change the default font size of her footnotes.
To set the default font size for footnote text, on the Home ribbon, in the Styles group, there is a small square button in the bottom right corner below the Change Styles button – the dialog box launcher.
Click that button, or press its shortcut combination Ctrl+Alt+Shift+S. The Styles task pane will appear.
If you cannot see Footnote Text in the list of styles, click the Options link in the bottom right corner of the pane. The Styles Pane Options dialog box will be displayed. Change the Select styles to show dropdown from Recommended to All styles. You may also want to change the sort order from As recommended to Alphabetical. Click OK.
Your Styles pane will now show a lot longer list of styles. Now right-click the name of the Footnote Text style and click Modify. The Modify Style dialog box will be displayed.
Change the font size to the required size, click New documents based on this template and click OK.