Type your title and center it.
Drop two spaces down to start the body of the outline, which will be single-spaced.
Set up the paragraphs so they are aligned on the left margin of your page with no indentation for the first line in a paragraph.
Check to see if your word processor has an automatic outlining feature that creates succeeding levels labeled "I.", "A.", "1.", "a.", "(1)" and "(a)". If so, familiarize yourself with how to use the feature.
Type Roman numerals I through III if you are creating the outline from scratch, with each in a new paragraph and each followed by a period.
Type a space and sample words after "III." The beginning of your sample text marks the left alignment of all text following Roman numerals. Create a tab that will jump to it and use the hanging indent feature of your word processing program to make sure that if text runs over one line, it will align properly.
Type a paragraph return, tab forward to the indent, then type "A.", followed by a space and text. Set up your hanging indent as before and create a tab.
Repeat the step for the "1.", "a.", "(1)" and "(a)" sub-levels so that each successive sub-level lines up on its left side with the text of the level that precedes it. This is your template, properly formatted and ready to use.