First of all, it is a good idea to read some of the great autobiographies that have been written.
It is important to consider who your readers will be, and then choose the tone.
It is very necessary to activate your memory and think about all the different periods in your life.
The chronology is something personal, some writers choose to list their story chronologically from their childhood to the present day, while others prefer to start from the themes or major events.
The writing should be descriptive. The best way to do this is to create a mental picture with your words.
Finally, it is important to follow a structured plan and keep your focus and motivation.