Conduct basic research. Depending on your story, you may feel you need to do in-depth research on a certain subject, like air force pilots in WWII or life in a refugee camp in Poland. However, resist doing too much research before you start your first draft. You may get overwhelmed by the amount of information you come across during your research and start to forget your personal take on the facts. Remember that your memoir should focus on your memory of the event, rather than be purely factual or completely accurate.
Create an outline or a graphic organizer of the major topics and ideas you want to cover. For example, you might make a time-order chart -- a chart with event blocks to organize events chronologically. Or, you might draw a cluster web -- a diagram with connected circles -- to divide your autobiography into sections, such as one for relevant background information, one for life-changing events, one for special memories and one for goals and dreams. Focus on reasons why specific events, situations and circumstances were important to you and how they made you feel.