If you're going to spend time writing and creating, I think it's good to take an honest look at what you do well and what you don't. Many of those things are subjective - is there a scientific way to break down good character creation? Probably. Do I know what it is? No. Do I know it when I see it? Sometimes. Let me start with something I don't do well: Proper character maturity.
Now there isn't a universal way any age group acts. I have raised 2 and one half boys (one is still a teen) and