INCREDIBLY SPECIFIC ADVICE

So, about original characters in fanfiction.

I… I’m not sure what to say.
The fact is that 90% of all OC fanfiction is full of Mary Sues, and Mary Sues are the worst thing to ever happen to literature. So in general when people ask me if they should write a story about an OC, I tell them no, they probably shouldn’t.
But uh… I hate to admit this, but some OC fanfiction is fucking awesome

Let me tell you something.
My favorite fanfiction writer is KidK. Thaaaat’s right. She writes self-insertion fiction. She even introduces a couple of OCs, too. Usually I wouldn’t give stories like this the time of day, but dammit… she does it so well.

So that’s my dilemma. I want to say to you guys, “Never write OC fanfiction ever ever ever!” but I can’t because what if I discourage someone who might actually be really awesome?
But there are so many really BAD fanfics out there with really annoying OCs and…
Uguuu….

Okay, I got it! Here’s what I’ll tell you guys:
DON’T WRITE CRAPPY OC FANFICS!
Ahh, it’s that simple~~

Ahaha.
Well, what I’m really saying is just to beware. Try to make sure your character is likable, balanced and not a Sue. You might want to consider including canon characters in your story, rather than having a cast of nothing but OCs (although I’ve seen that done well too…). Try to give your character a backstory that isn’t entirely contrived, and introduce them in a way that isn’t awkward. Having your character be a long-lost sibling of another character is a no-no (especially if they’re Zim’s long-lost sibling, since Irkens are cloned and therefore either have no siblings, or EVERY Irken is his sibling. Either way, you look dumb).
Just… put some thought into it. A lot of thought, preferably.

… and please please please don’t break up a canon relationship just so your character can have a canon character all to his/herself, please….