Since I wrote about villains, I guess I should address something on the other side that I see a lot.
Much hay has been made of stories that teach about failure. Mind you, the failure is not really the fault of the hero, so while it can be interesting because yes, outside forces will screw you no matter how hard you try, I feel the frequency of this story misses out on another truth: sometimes, you failed because you were wrong.
Yes, sometimes in life good people are wrong about things. This is a theme of a relationship between one of the main characters of Paladin and a secondary one. It’s a rather stupidly human thing to do and that’s why I like it.
It’s okay and even interesting to write heroes who make the wrong call about people or situations. Dealing with failure is one thing; dealing with a failure that is your fault, your actual fault because you were wrong about something, is another.
This is what is meant by flaws. Not clumsiness or too much cursing or a weakness for chocolate or whatever. Those might be problems and they’re certainly relatable, but they’re also overplayed (interestingness I leave to you). If you’re looking for a didactic angle, they’re better corrected by a self-help book or a therapist than your story; stories teach different kind of lessons.
Also, if your character feels like they’d be making a bad call, then let him or her make it. Your character doesn’t need to be an archetype. People know the archetype! But they don’t know the person you’re writing about yet. They’ll make a more impactful role model, too.
Luke Skywalker was whiny and selfish at the beginning of Star Wars, but by the end of the trilogy he was able to selflessly put that aside to face death and worse. That means a lot more to a lot more people than starting and ending with some paragon; a lot of them know they’re at least sometimes whiny and selfish and, frankly, they shouldn’t be, they may not realize that they can overcome it. Show people that people can overcome real character flaws, survive their own poor judgement, and live- a happy life, even- with the fact that they are the source of their own failures.
Plus it is a lot more interesting. There is no challenge like overcoming yourself, in terms of both difficulty and the glory that comes with success.