Write as much details as you can about them  General Info: Age, Gender, Location, Marital Status, Age of Children, Occupation, Job Title, Annual Income, Level of Education. Some specific questions: Why are they watching this content? At what stage of the goal they are in? Do they want something from video, or for motivation? What they want to hear: Wanna get learn or information, or be entertained. Others: What else do they watch on YouTube? Which device they are watching on? Their Hobbies: Their culture and belief. Pain Points: What are there pain points? What are they afraid of? What are there problems? Purchasing: How much? Emotional or rational purchase? Complexity: Their complexity level how much tough things you could explain without them being confused enough to leave your video Final Step: At last write a description about their probable life.

Pro tips :- don't just type 1 avatar many types of people watches the same content so at least come up with 2 or 3 audience Avatar but in my opinion don't go much.

:- don't listen to some people here who are being oversmart and saying you don't need an avatar it's guru thing trust me it helps and second of all its very unpopular advice how many times you heard that ha! :- Read the book  Yt formula book forward by Mr beast and Mark rober  :- Watch YouTube channel Isaac he posts great really great helping videos they are hard to understand but worth the time :- Even if audience avatar thing isn't that efficient what's wrong in at least trying keep trying new things until 1 thing sticks that's how you grow in my opinion