Best practice is to use sans-serif fonts, rather than serif or decorative fonts. Sans serif do not have the decorative lines. The fonts would include Arial, Calibri, Century Gothic, Tahoma, and Verdana. The font size should be 24 pt font for the body text. The font could be larger depending on the audience or page layout.
PowerPoint has built-in slide designs that contain placeholders for text, videos, pictures, and more. They also contain all the formatting, such as theme colors, fonts, and effects. To make sure that your slides are accessible, the built-in layouts are designed so that the reading order is the same for people who see and people who use technology such as screen readers.
On the View tab, select Normal.
In the Thumbnail pane, Right-click, and select New Slide. Select the "New Slide" for a new slide.
On the Design tab, expand the Themes gallery, and select the slide layout that you want. PowerPoint automatically applies this layout to the new slide.
Select one of the themes and the selected theme will appear. If you are doing this at the end go through to make sure all information has been formatted correctly.
Your new theme has been applied.
To View and Listen to a Video Tutorial:
Select the link below to watch and/or listen to the tutorial:
How to Video for Using Built-In Accessible Slide Designs in PowerPoint (00:01:07)