How do I format my three levels of headings?

Headings need to stand out but also be uniform, so they are easy to distinguish from the other text. So how should you format your headings? I did the research for you and have listed it for you here. 

Formatting level 1 headings

Level 1 headings should be:

1. Boldface
2. Flush left
3. 150% of the regular text sizes

Formatting level 2 headings 

Level 2 headings should be: 

1. Boldface
2. Flush left
3. 125% of the regular text size

Formatting Level 3 headings

Level 3 headings should rarely be used, and should be:

1. Indented
2. Boldface with period
3. Text should begin after the period

After reading multiple sources, I came up with this formatting. It primarily uses information from "Letting Go of the Words" by Janice Redish. However, it also coincides with standards from APA style guide and MLA formatting guide. I also looked up the Chicago style heading formats, but it is not as similar to what is given to us by the other sources, so I chose something that will follow the advice provided by Janice Redish. 

Differences between style guides for headings

In case you wanted to see the difference of suggested heading formats, I have supplied an outline of APA, MLA, and Chicago style guide's heading formats below. I have also linked them to the sites if you would like to look at the information yourself. 

MLA(link)

Level 1: Bold, Flush left

Level 2: Italics, Flush left

Level 3: Boldface, Centered

APA(link)

Level 1: Centered, Boldface, Uppercase and lowercase headings

Level 2: Left-aligned, Boldface, Uppercase and lowercase headings

Level 3: Indented, Boldface, lowercase headings with a period. Begin body text after the period.

Chicago(link)

Level 1: Centered, Boldface or Italics, Headline-style Capitalization

Level 2: Centered, Regular Type, Headline-style Capitalization

Level 3: Flush left, Boldface or Italics, Headline-style Capitalization