There are a couple of truisms in fiction, and one of them is “stories are about people.” I’d say “Most stories…” but unless you’re really setting out to write something like Islandia or Utopia or Voyage to Arcturus, you can pretty much go with the truism. This means that learning to write “good characters,” or writing “good characters” even better, is a major focus for all writers, whatever stage of development they’re at and whatever sort of fiction they write.
The trouble is that how one goes about writing “good characters” depends both on the type of writer and on the sort of story one is writing. Some writers have to develop their characters very methodically and in a lot of down-on-paper detail, starting with their birth, childhood, home environment, etc. Others have characters walk into their heads with their personality and appearance fully formed (though they may have to dig for details at certain points in the story). Still others begin by “casting” their characters, basing them on their favorite actors (or on favorite characters played by those actors) and then letting them develop in their own directions as the story progresses. And others “write their way into” their characters…and then have to go back and rewrite the early part of their story where their people were cardboard.
The type of story also has a big impact. Realistic, deeply realized, well-rounded, fully developed characters are seldom suited to a parody like Cold Comfort Farm or a light comedy like P. G. Wodehouse’s Bertie Wooster stories. (OK, Jeeves and Bertie, Flora Poste and the Starkadders are certainly fully realized, but realistic and well-rounded they are not. Which is part of the point and the fun.) Conversely, populating a serious drama with over-the-top stereotypes is unlikely to work well in most cases.
So if one is having trouble with one’s characters, the first step is to figure out what kind of characters will work with whatever story one has in mind. Are you going to be better off with comic exaggeration or a more realistically rounded set of people? Most stories aren’t homogenous – they don’t have only comic characters or only realistically rounded ones or only stereotypes. Think about what mix is going to work most effectively in your story.
If you have a plot, or the skeleton of a plot, you can start with the central characters you know you need – say, a villain, her chief minion, a hero, and his sidekick. You know what their roles in the story are; to make them more than their roles, to make them characters, you need to know what they are like as people. As individuals.
The exact way you approach finding out what each character is like will depend on how you work. If you are a casting-call sort, you start by considering all the TV and movie characters and actors you know, and figuring out who you’d want to play each part in your story. If you are a “walk-into-the-head” type, you can probably ignore everything else here, because you already know what your characters are like. But the methodical-development process can be useful for anyone who’s stuck, if only as something to make your backbrain scream “No! Not like that! Like this!” so that you can get on with things.
For this, you start with one of your major characters – the villain’s chief minion, say – and look at what the plot requires him to be. Then you invent some backstory for him, based on what you know about the story and the world. How did he meet the villain? Has he been with her since she started her villainous career, or did he sign on once she already had her evil organization up and running? Did he work his way up through the ranks, or did he hire on at a high level to begin with? Do you need to know anything about his childhood? Does he have any personal grudges against any of the other characters? Is he content to be Chief Minion, or is he plotting a takeover? How does he present himself – is he sleek and smooth-talking, or is he a brute force kind of guy? What does he like doing for fun that’s not evil and villainous?
Some of the answers you come up with – like whether he has personal grudges against other characters, or how he met the villain and became her Chief Minion – will affect the backstory of other characters. Some of it may require tweaking the worldbuilding so that there suddenly are pirate magicians in this world, or some other thing you didn’t previously know about that you need in order to give Chief Minion the background that feels right, and that gives you a feel for what he’s like. These are not set questions; you ask yourself whatever you need to ask in order to get to know the character. If he has a ragged scar across the left side of his face, but you already know that it doesn’t have anything to do with what he’s like or with the plot, then you don’t have to waste time coming up with backstory for how he got it. You need to know what you need to know so that you can write the way this character moves, talks, acts, and thinks, and so that you know what kinds of choices he will make.
Once you’ve gone as far as you can with that character, you move on to another one and go through the same process. You may not yet have enough to really write Chief Minion yet, but that’s all right; you can circle back to him later, when you have at least some background/backstory on each of the other characters. In fact, you probably will have to circle back, because unless all these characters are complete strangers at the start of the story (and Chief Minion really ought to at least know the villain by then), things you make up for one of them can affect the backstory for others, and the tweaks you have to make to the worldbuilding for the sidekick’s background to work may have a ripple effect on the villain’s background, and from there to the minion’s. Or you may come up with an idea for the hero that doesn’t feel quite right for him, but that suits your Chief Minion admirably.
Every so often, you will hit something that you just know is the way things are. My current viewpoint character is the eldest of at least three children, has an uncle she adores for various reasons, and is currently an apprentice seamstress. Lots of things can change about this character, but those elements are set in stone. I also currently think she was brought up in the country, that her mother is emotionally fragile, that she gets on well with the woman she’s apprenticed to; I’m still waffling on whether she has magic, but I’m leaning toward yes. Those things can change if I think of something that feels as if it fits better than what I’ve decided so far.
If you are having trouble with a particular character at this point, it can help to scrape everything back to the stuff you are absolutely positive of, the stuff that your backbrain screams “NO!” at you if you even think about changing it. For Max, that’s two younger siblings, being an apprentice seamstress, and the uncle. If you have quite a lot of development done, but it just isn’t gelling, start from the stuff that is rock-solid and try on alternatives for everything else. I thought she was a country girl; maybe she’s always lived in the city. I thought her father was dead; maybe he just disappeared, or maybe he’s still around as a respectable tradesman or a soldier; maybe he abandoned the family; maybe he faked his death. Lots of those alternatives would affect the plot, but I’m not worried about that at the moment. I’m worried about what feels right as Max’s backstory, the stuff that I can point at and say “This is what happened, and it’s why she’s like that.”
I tend to approach my characters through their stories – that is, I think about the things that have happened to them, and then think about the ways it might have made them turn out. It is perfectly possible to do it the other way – to decide that your character is shy, or intellectual, or bad-tempered, and then come up with incidents from their past that will explain how they got that way.
The whole development stage eventually turns into a round-robin, with the worldbuilding changing to accommodate the background for the Chief Minion, which affects the plot, which affects what the hero and villain have to be like, which affects their backgrounds, which affects the worldbuilding again. If you keep going around and following all the ripple effects, they eventually get smaller and smaller (usually). At some point, you will have enough information to go on with; at that point, or perhaps one round after, it’s a good idea to, well, go on. You can keep chasing tweaks and ripple effect stuff forever if you don’t set yourself some limits. And really, you probably don’t need to know what kind of ice cream they served at the hero’s sixth birthday party. You just need to know that the hero now likes strawberry better than chocolate.