OUUROBOROS

Sort of promised in my earlier 'Assorted Writing Tips' post, I finally got around to creating this! Some of the things I do to make well-developed, non-Mary-Sue characters. At least, I'm pretty sure they aren't Mary Sues! Everyone who reads my material tells me they aren't when I ask and I have a set of friends who are brutally honest about everything,  so I'm taking that as a I-actually-do-pretty-well-at-character-dev.
I've been writing for a long time! Since I was eight, I wanted to be an author. And, just like everyone, I've made some unintentionally horrible characters. Characters that make me cringe now! 'How did I ever think this was a good idea, reading this is painful' kind of cringing.
I've also made some intentionally horrible characters as jokes, see Fuschia Jones.
So, here we go. ~

First, an incredibly useful resource. It's the Mary Sue Litmus test, found here! It's also pretty fun to do - I put most of my characters through it to procrastinate on stuff.
I suppose what is needed now is a definition of Mary Sue. If you already know, skip this section~

A Mary Sue is, quite simply, a perfect character - and sadly, they are rampant. Especially amongst younger writers - including younger me!
They are born out of author favouritism. A Mary Sue is, normally, without flaw - if any are present, it only serves to make the character more appealing to the audience or really detracts nothing from their overall character. An example is Bella Swan from Twilight - her only real flaw is 'clumsiness'. All this does is make her more attractive to Edward Cullen (another Mary Sue) who feels as though he has to protect her even more.
In fact, why not use Bella and Edward's whole characters as the definition of Mary Sue? Meyer's vampires are also the definition of a Mary-Sue species. They get all the strengths of most vampires - super fast, super strong, perfect predators, immortal - and none of the weaknesses (turning to ash in the sun.) For an already overpowered species like a vampire, this was always the great equaliser. But Meyer's vampires can also elect to drink only animal blood, allowing them to be unequivocal good guys and never really have to toe grey moral boundaries!

A Mary-Sue character gets everything. They always win. They are often the most beautiful and may even lament their beauty 'as a curse' (presenting something that isn't a flaw as a flaw, common tell-tale), or refuse to accept compliments as a forced show of modesty. They are the best at everything, or get extremely good at things very quickly without much effort. Nothing really goes wrong for them, at least, nothing drastic (though another tell-tale is them having an extremely tragic past and either dwelling on it constantly to force pity, or being completely unaffected by it.) They save the day more than any of the other characters combined, their abilities make them extremely overpowered in their respective world. Often the character will be a blatant self-insert of the author, who wishes they were as great as this character. In short, they are EXCRUCIATINGLY ANNOYING.

We don't want to be writing any of those.

A well developed character is one you can imagine as a real person. Riddled with imperfections and flaws, but real. Don't be scared to write outside of the good/evil box - not everything is black and white. Characters can make questionable decisions, suffer from flawed logic, frantically try to justify themselves even when there is no justification - or simply revel in the fact that there is no justification. Just because they're a flawed, terrible person, it doesn't mean they are a bad character. They can be an extremely well-developed character, warts and all, and even if you would never be friends with them in real life it shouldn't stop you appreciating them as a character.

So, focus on imperfection.
Not every character has to be perfectly beautiful! I already focused in my writing tips post on not being cliche about your descriptions, and cliche descriptions are a hallmark of the Sue.
Exploit the flaws.
Exploit them to the maximum! Yes, each character has good points - determination, courage, intelligence, kindness - but flaws are so much more interesting. Is your character a coward who only redeems himself after a valiant struggle to be brave? Or do they fail? Does the flaw overwhelm them? Don't be scared to have a character lose!
Or, are they a brave character who loses their nerve at a vital moment, and fails?
Are they arrogant and cocky? Do they hide away their emotions behind a mask of indifference, only to have it crumble and them despair? Do they recover from this, or not? Are they manipulative little shits who get tangled in their own web of lies? Do they have a big mouth?
And if so - why do they have a big mouth?

Why is your character they way they are? This is perhaps the most important question of all! WHY is your character as they are, and how is this motivating their current actions and desires?
I cannot stand characters who have no motivation for what they are doing in stories!  We don't do things for no reason at all. I especially resent characters who are evil 'just because.'
Why?
To create three-dimensional, realistic characters, you have to understand real humans. I never write a character who is 100%, 50%, even 10% me. But a lot of them will have an aspect of myself, one that I understand and can apply to them. Some of them have aspects of my friends or family, or other people I know.
For example. (Using characters from my upcoming trilogy, the Light Age)
Hoy is a loud-mouth. He's obnoxious, he bigs himself up, sometimes tries to put others down. He exaggerates his own achievements, acts all tough. His big mouth gets him into a whole heap of bother when he picks fights with the wrong person or winds up having to actually walk the talk. Because underneath it all, Hoy is a massive coward, and cannot follow through on his boasts.
The reason he has a big mouth and tries to act tough is that he is fundamentally ashamed of his cowardice.
His father was extremely disappointed in him. He wanted his son to be strong and tough, but Hoy simply was not. Even after the death of his father Hoy values people based on courage and strength - qualities he doesn't really possess for himself. So he acts like it, he puffs himself up and struts around, tries to make everyone see him as brave and strong so that maybe he himself can believe it.
He just wants his father to be proud.
That's his motivation. That's the reason why he is the way he is.

(Yes, Hoy ultimately overcomes his cowardice. Even though it's the hardest thing in the world for him to do. Never let it be said that my characters always meet bad ends or fail!)

On the other hand, Rosita.
She's the 'big bad' of the series, the military dictator who rose to power on the back of a wave of lies. Extremely intelligent, genius-level intelligent - and arrogant as hell.
Her intelligence bred arrogance, in this case. She was light-years ahead of her peers, and ultimately came to see them as beneath her. She values people based on intelligence, and sees herself as worth more than everyone else. And once you put yourself above others, you can be cruel to them without feeling a shred of guilt.
You see it as your right - and ultimately, via a long and complicated series of events that I won't explain here, she comes to see power as her right too.
She wasn't always bad - in fact, she sees herself as being one hundred percent in the right. She was always a grey character, a grey-area. Her parents were industrialists who instilled in her the belief that personal profit meant more than anything else - the world's a shark-fight, biggest fish win. If not her, then someone else. As a rather high-functioning sociopath, she is only able to care about herself. And this vanity and narcissm, plus her intelligence-generated-arrogance, led her to do terrible things to other people for personal gain.
She doesn't see anything wrong with it. I was going for a WW2-holocaust type theme here - once you see someone as beneath you, you can do the most terrible things to them. It's almost sad - she could have done extraordinary things for the good of all, but circumstance and her upbringing and the way her mind was wired shaped her into a selfish little madam. It could have been different.
But in the end, for all her intellect, Rosita's arrogance is her downfall.

You see? It's so much more interesting to have fundamentally flawed characters, rather than super-talented-super-pretty-super-modest-always-the-hero characters. The only way you could have a super-talented-super-pretty character is if they were not super-modest. If you're very good at many things and extremely pretty to boot, you are probably not going to be modest. It's more likely that you are going to be an arrogant little so-and-so.

This is another thing that upsets me. Inconsistent or unrealistic characterisation.
If your character is big-mouthed and bolshy and dishes out verbal retribution to others, it's likely that this won't always be justified. Sometimes they're going to be mean, say things that go too far or are undeserved. Otherwise they aren't really big-mouthed, they're just overly righteous.
Think about real people, and how real people really are!  We're all complicated, and we're all individual. Try thinking about yourself, and all the facets of your personality. You know yourself better than anyone else. Why are you the way you are? What happened to you to make you this way? What are you doing now? What is the reason you are doing this?

So, in short - ask questions! Ask lots of questions! Questions are good.  ♥‿♥
And never be afraid to write a character who isn't the 'norm'. They don't have to be beautiful - they could be rather unattractive. And that's okay.
Maybe that unattractive character could be pretty hung up over it? Maybe they apply tons of make-up to feel beautiful - is that really so abnormal in today's image-obsessed society? Maybe they act as though they don't care, but really do? Or maybe, they genuinely do not care. Looks are just not important to this character, and they aren't going to go out of their way to look any better.

Limitless possibilities! Just have fun with them! ♥‿♥
If you aren't having fun, why are you writing in the first place?

Whoops, this post was longer than intended. I'll think of more things to post soon! ~
I hope it was useful.