Determine the key actions and obstacles in your story. Once you have a sense of what desire or want you want to explore in your memoir, you can identify the actions and obstacles your narrator must overcome to achieve the desire line. Obstacles or challenges will give the story stakes and motivate your reader to keep turning the pages of your memoir. You are the driver of the action in your story and a story isn’t very exciting if it doesn’t have any driving action.[4]

Limit it to 15 minutes, no more – at least at first. Fifteen minutes, three times a week, always at the same time and always in the same place. Stay there for all 15 minutes even if you can’t think of anything to write.  This will set up a rhythm, in the same way we get hungry at mealtimes whether or not we’re really hungry. This isn’t just about finding time to write your life story.
After considering these factors, the next step is writing a draft. Start by looking through the best autobiography openings you can find and figure out which you can use as a model. Make sure that you write in the first person since that’s what autobiographies are all about. Never switch back to second-person or third-person and be consistent in using the first person point of view throughout the entire content.
Once you have taken a look at your own life from an outsider’s point of view, you will be able to select the most interesting elements from your notes to establish a theme. What was the most interesting thing you came up with in your research? Was it the history of your family and your region? Here is an example of how you can turn that into a theme:

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.
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.
Writing your life story can be one of the most complex forms of storytelling. It could involve emerging themes, narrative flow, and re-creating dialogue from memory. Or it can be surprisingly easy and fun. What if I was to show you a powerful and unique method of capturing a dynamic life by using legacy themes? It involves just ten of these. Best of all, these legacy themes are easy to write with only 2-3 pages for each. If you have ever written a high school term essay, you can write your life story.
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.
Pull out the best stories. The story of your entire life would start to get pretty long-winded, so you'll have to make some decisions about what anecdotes you're going to include. Begin drafting your manuscript by writing out the main stories that will be woven together to create a picture of your life. There are a few main topics that most autobiographies cover since readers find them fascinating.[1]