The consequence(s): Ask yourself, What disaster will happen if the goal is not achieved? What is my protagonist afraid will happen if she doesn’t achieve the goal or solve the problem? The consequence is the negative situation or event that will result if the goal is not achieved. The combination of goal and consequence creates the main dramatic tension in your plot. It’s what makes the plot meaningful.
For example, if you grew up on a farm, you know the difference between the smell of hay and wheat, and certainly that of pig manure and cow manure—because you had to shovel one or all of these at some point. City people probably don’t even know there is a difference. Describing the subtle differences of each and comparing the scents to other scents can help the reader imagine the situation more clearly.
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.
What's your central conflict? What's the biggest obstacle life presented that took years to overcome or come to terms with? Maybe it's an illness you were diagnosed with at an early age, a relationship wrought with turmoil, a series of career setbacks, a goal you worked for decades to achieve, or any other number of things. Look to your favorite books and movies for more examples of conflicts.
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.