Once you have your initial list, elaborate on each key event in your outline. If you're using the autobiograa, fill in the blanks, and then write anything you remember about that point, a little or a lot, whatever springs to mind. Later, you might choose a single event that best illustrates each point in the outline and describe the event, using your theme statement to guide your description.
As is present in the biography of a person, your place and time of birth, your parents’ views, an overview of your personality, your likes and dislikes, and important events that shaped your life should always be included in your autobiography. This will give a mental picture of your life to the readers as a sort of backdrop to the main part of the story.

Develop a central theme, main idea or thesis that clearly explains the purpose behind your autobiography. For example, your theme might be about how you overcame obstacles to become a stronger person, or it might explain why a particular passion -- such as mountain climbing or rescuing animals -- is so important to you. Back your theme with details and background information about your life experiences. For example, you might explain that your dad is in the military, so you've had to learn how to adapt quickly to new schools and unfamiliar environments. Or, you might discuss what it was like growing up in a poor, single-parent home, but how your family was always willing to take in injured or stray pets.