Decide on a length for your biography. If the biography will only be several pages in length, you will have to limit the information you include to only highlights that can fit in this space. If the length of your biography is not a concern, feel free to go in depth about seemingly mundane events that have shaped your life.
Keep a daily journal. This will provide you with information you can refer to when trying to keep your biography accurate. To help trigger memories of past events, look through old photographs, as well as peruse diary entries and mementos.
Create a time line of your life. Unlike a memoir, which usually only focuses on a certain period in a person's life, a biography spans from birth to death—or until the time in which it was written, if it’s an autobiography. Make note of significant happenings in your life that have made you the person you are today. These details will help your biography take shape.
Get inspiration from friends and family members who have been a part of your life. People such as these can not only help trigger memories or provide information on past events that you might have forgotten, they might even give you useful quotes that you can incorporate into your autobiography.
Focus your autobiography on a recurring theme of your life. Once you document your past, you can begin to see who you are in the present and who you would like to be in the future. What important lessons have you learned along the way? How would you want people to remember you? What would you like to share with the world? Asking these questions can help you focus the theme of your autobiography.
Do not lie or sensationalize your own story. It’s easy to get carried away and embellish, especially if your recollection of certain events is a little hazy. Try to support your biography with source material that will corroborate your claims. A biography with too much embellishment is not a biography at all, but rather a work of fiction.