Recipe: How To Cook An Excellent Character

Ingredients:

Likes / dislikes

Mannerisms

Personality traits

Habits

Appearance (used as garnish)

Obstacles

Wants / desires / needs

Backstory

Thoughts / opinions

Changes over time

Method:

If you are the type to use “character sheets” or “character interviews” before starting to write your story, and you find it helps, use those. I’ve personally never got on with them. I like to discover things about my characters as I’m writing scenes — it feels more organic that way. You don’t automatically know everything about someone in real life before you meet them. Anyway, I like surprises…
The main thing integral to the story is what your character(s) want or need, and the obstacles that are preventing them from fulfilling that want/need. For example, a superhero who needs to save the world by climbing a volcano, but struggles to do so because they lost the use of one of their legs. As the story moves along, the superhero finds a way of overcoming such an obstacle (perhaps by gaining the powers of flight).
The second most integral thing to the story (or perhaps equal to the previous ingredient) is backstory. Readers want to know why characters are the way they are, and why they think certain things, and why they behave in certain ways. Especially villains. The bad guys tend to be the most interesting characters in stories as they take the road less travelled and commit actions we couldn’t fathom in reality. Important: you don’t have to include the entire backstory if the story doesn’t need it. If you try to wedge a character’s entire backstory in, you end up with a massive info-dump. Drip feed details of the backstory to the reader as you go along. For example, our superhero lost the use of his leg from contracting polio as a young child. He was one of the last known cases, which adds a lot of bitterness to his thoughts and feelings about it.
Changes over time are also equally important. No person stays the same. Life changes everyone. The story should cause the character to realise something about themselves or discover something within them, and their actions / behaviour should alter accordingly. For example, the journey to obtaining the power of flight makes our superhero realise he can do anything he can put his mind to, and his new-found self-confidence changes the way he treats other characters. He no longer stays at home moping about his leg or resenting his circumstances, but starts up a charity for disabled people.
The other ingredients — habits, mannerisms, likes / dislikes, personality traits, thoughts / opinions aren’t as important. Think of them as seasoning. They provide something about your character that makes them different from characters someone else would write and makes the reader want to spend more time with them. The story doesn’t depend on whether our superhero likes spaghetti and meatballs, or hates alien conspiracy theories. It isn’t vital to the story that he always wears odd socks or starts brushing his teeth from the left side of his mouth every morning. We don’t have to know whether he has a facial tic or whether he thinks his dog is clever enough to win prizes. So use a few of these details in the story, but don’t over-saturate it with them, otherwise the reader won’t be able to taste the plot.
Appearance is even less important (unless it has something to do with the character’s wants / needs and the obstacles they have to overcome). A lot of stories I like to read just give a couple of specific details about the character’s face and / or body language and that’s it. Think of the character’s looks as garnish. In fact, the more details you put in about how they look, the more likely you are to put the reader off, as readers like to identify themselves with the character they’re reading about / from the viewpoint of. An exception to this is if their appearance is so different to everybody else that it has to be remarked upon, e.g. if they’re an alien species, or if they are a character your protagonist is falling in love with and they can’t help noticing how they look. We don’t need to know if the character’s eyes are “azure blue with brown flecks and little lights inside them” — just say they’re blue and move on.