Use printouts to provide supportive details. Determent a color scheme. Printing colors directly on blue film may muddy the colors For black and white output, substitute shades of gray and textures for color. Orient slide horizontally, not vertically. For screen presentation, the upper left an center catch most attention, the main idea should be placed there.
Viewers usually read from top left to right yet viewing preference various among countries.
As a general rule, font size should no smaller than 18 points and depend on the font style. Pre-viewing your presentation is recommended. The layout should be consistent throughout the presentation. It states the main idea and helps you get your idea across. PowerPoint is ideal to be used in various situation.