When writing characters, I have two main approaches, though they sometimes blend. Do I need a particular character for my story, or do I need an archetype? If I need a specific character, I will generally start with a rough draft, visuals, behavior, flaws, and virtues. And slowly add to it, until I have reached a point where I am happy with it. Depending on what I need, this can take a while.

The way of creating a character I enjoy more, though, is far more hands-off. I am starting with a theme or a role. Maybe I need a captain for a ship that will fight an ancient evil. So I push together a rough draft, often stereotypical and start writing/interacting with the character. This can be anything that forces me to think about a character, from writing a short story, over having someone else ask this character questions. I feel like asking the character themselves is better since it forces me not only to consider the answer, but how the character would react to and answer this question, to throwing the character into hypothetical situations.

This way, I approach the whole thing more open-minded, allowing the character to develop a mind of its own, a momentum that I can use to my advantage. I can still keep the character on track for what they were once meant to be, and yet can have them change in unexpected directions, or ways I would not have considered when building them statically.