Organize what you've written according to cause and effect and action and reaction. Ordering events according to cause and effect is a natural process. Your car broke down, so you called a tow truck. That's cause and effect. You received a promotion, so you bought a house. Action/reaction happens paragraph by paragraph. He said "No," so you said "Why?" That's action/reaction. She set a wet glass on the table, so you placed a coaster under it, and remembered how your mother used to crochet pretty little coasters and starch them. That's action/reaction.
Have you ever read an autobiography? Benjamin Franklin’s autobiography, for example, is an exceptionally powerful one. “DEAR SON: I have ever had pleasure in obtaining any little anecdotes of my ancestors.” That’s how it starts. But, Benjamin Franklin was an exceptional person, after all. That’s the point: autobiographies are for exceptional people. You’re exceptional, too. You have a special story that’s worth sharing. The only thing to learn is how to write a life story about yourself.
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.