Take a step back to reflect. You're chronicling your life lessons, but what have you learned from them? Relay your intentions, desires, feelings of loss, feelings of joy, the wisdom you've gained, and other inner thoughts from time to time throughout the book. Taking a step back from the action of the story to reflect on what it all means is a good way to add depth to your autobiography.
These memories are also important because they point backwards to what was, and forwards to what was about to happen, with a sense that there was now a new way of seeing these stretches of time. In each memory, moreover, there is likely to be a huge gift – each will reflect a theme, possibly a major theme, which will play out in the rest of the writers’ life.
Many people cannot resist the temptation to tell as much as they can, but a longer piece of writing doesn’t always equal a better piece of writing. For whatever reason you are writing the autobiography, think of the person who is going to read it. Imagine you were an admission officer or the judge in the scholarship committee, and you have to choose from hundreds, if not thousands, of autobiographies. At some point you will hate people who prefer to write long admission essays and autobiographies. There’s also a good way to check whether your writing is interesting or not. Give it to one of your most impatient friends, who prefers short articles to books and long stories, and ask for their opinion.
Be revealing. You don't have to be explicit, but it's important to reveal truths about yourself and your life in an autobiography. Don't let the book become a list of your accomplishments, with all the negative material carefully kept under the rug. Present yourself as a whole person, sharing talents and flaws alike, and your readers will be able to identify with you and hopefully root for you as they make their way through your story.
Write out your life timeline. Start writing your autobiography by conducting research on your own life. Creating a timeline of your life is a good way to make sure you include all the most important dates and events, and it gives you a structure to build upon. You can consider this the "brainstorming" phase, so don't hesitate to write down everything you can remember, even if you don't think the memory will make it into the final version of the book.