All of your titles should use the same typeface, weight, size, style, and color. Titles should be the largest text on your slide. Titles should draw attention at the top of your slide because it is the point that will be elaborated upon. The title location should remain consistent throughout. Do not type titles in ALL CAPS because it is difficult and slow to read.
Subtitles are an expansion of the title.
Use text that is smaller than the title and place it consistently in the same place on each slide. Body text should be slightly smaller than the title. Don't overload the slide with too much text. It's better to have two readable slides than one unreadable slide with too much text on it. Y our text should be as consistent as possible throughout your presentation.