Identify your audience. To create an effective bio you need to determine who will be reading your bio and what impression you want them to have. The purpose of your bio will help identify the audience. For a job application the audience will be employers, for a speaking engagement the audience will be comprised of people interested in the topic you are speaking on.
Start by writing the story of your life for yourself first. After you edit and polish it, share it with a few trusted people. Then, after you edit and polish it again, share your life story with a wider swath of people. This will help ensure your memoirs are your best possible work, and that your writing is something you’ll be proud of at the end of your life.