If you have headings in a document, it is a good idea to be consistent in your formats. You can apply these under Themes (see under Design) or within the Styles screen under the Home tab. Note that the Styles screen will be governed under the overall Theme, and therefore you are not restricted to the font and format that you see in the Styles screen. However, you should apply a heading hierarchy (levels of headings) using the Heading 1, Heading 2, and sometimes Heading 3 styles. If the font is not the one you like to use, and the position of the heading is not how you want it, then you can modify any or all the heading styles.
You may wonder why you need to use the heading styles. The simple reason is that if you want to produce a table of contents (TOC) later, it will find the styles and produce a TOC automatically. Also, all the headings will show up in the Navigation Pane, allowing you to quickly go to any part of the document at the click of a mouse button, and even swap chapters or sections under each heading.
So, how do you modify the heading style? Ensure that your cursor is within the relevant heading first, then go to the heading style and right click on it up at the top of the screen under the Home tab. Click the Modify option which will show a pop-up window with all the options to change the font, alignment and so on as shown here.
The only part you should be concerned with is under the ‘Formatting’ title where you can change the font, the size of the font, make it bold, italics or underlined; then decide whether to place the heading to the left, right or centre. When you have made all the changes that you want, press the ‘OK’ button, and the style will be modified. You can then use that style throughout the document to duplicate the heading style that you prefer. Note that Heading 2 and Heading 3 styles should differ from Heading 1 and be smaller point sizes respectively. They will also be sorted according to their levels in the Navigation Pane. That means the sub-headings will show as indented from the major headings, giving you a clear view of the headings hierarchy.