1. Outlines The primary benefit of writing outlines is to save time.
The outline allows you to get feedback before you have invested too much time into writing your essay. It is much easier to change an outline than it is to write a new draft.
You should be able to write the outline and someone should be able to read the outline quickly (that is the point).

2. Outlines
Someone should be able to identify your document as an outline without reading a single word. Outlines have a distinctive form.
Short entries
Indentations to show subpoints

3. Outlines
The outline should allow me to make judgements about the organization of your essay.
Chronological order of events
Order of paragraphs
Estimates for lengths of paragraphs
Estimate for the length of the essay
Paragraphs that stay on topic (points should not contain multiple topics)

4. Outlines
Make sure that you provide context (time, place, character) early in the essay.
Points of the outline should refer to events. Events are not ideas. Events occur in a single point in time.
Most likely the events are turning points.
You will have many paragraphs (around ten)
For now, do not include an introduction in your outline. Begin with the earliest point.