Choose the focus of your autobiography and the events in your life you will write about. Outline those events in the order they'll appear. The mundane events that come with living are there for all of us and important only to those who live them. Keep your story interesting by only including what is unique to your story.
Plot your autobiography creatively. Order the events as if you're telling a story. Forget about chronological order. Think about a beginning, middle and end. Consider breaking your autobiography into several major chapters that cover specific periods of your life and add sub-sections within those chapters that cover events that shaped those periods of your life.
Keep it colorful. Don't just stick to the facts. Engage your reader with writing that draws them in and makes them feel as if you're telling them a story. Don't make up events in your life, but a little creative license can go a long way. This can often be achieved by combining events in your life to make them more interesting or to better pace the telling of your story.
Treat the people in your autobiography as characters in a novel. Find the traits about them that made you love them and show those traits to your readers.
Don't wander. This isn't the time to reminisce. Tell your story in a smooth-flowing narrative. Keep the focus on that aspect of your autobiography that made you want to write it to begin with.