In my opinion, the most important thing about a character is WHO that character is... which stands in contrast to WHAT the character is. As Batman says, "It's not who I am underneath but what I do that defines me." Sloppy attempts at inclusionary storytelling and forced representation all too often fall into the problem of missing that, and having their characters be a WHAT first and a WHO a distant second. I've come up with a theory that for any character there's a "Cost" in design elements, and if you don't spend enough they're probably bland or under-described, but if you spend too much you haven't left a lot of room for the WHO because you're working with a WHAT that's more notable.

The 0-cost character is the AFGNCAAP - Ageless, Faceless, Gender-Neutral, Culturally Ambiguous Adventure Person. The AGGNCAAP has no traits at all, they're a totally generic subject to verb objects, or possibly object to be verbed by other subjects. They're also not terribly interesting, and generally only plausable at all in second person narration -- as "you". I suppose the verbs that occur throughout a story may define some traits of the AFGNCAAP; we might learn it has hands (or at least graspers) when it holds something, or functional legs of some description if it runs.

Anything else, ANYTHING AT ALL invokes a cost. And you want some cost -- not enough cost you're still left with a blank slate, and probably don't have a foundation of WHAT to start building WHO on top of. The more specific your description, and the more divergent it is from what your readership could expect, based both on your readership (Ideally the sum of all human beings on earth) and your setting. For setting, take (biological) Species/Race: Human costs almost nothing, so little that it can hardly be noted, in anything set in a supposedly "real earth" setting. It costs more in Speculative Fiction, but still less than the alternatives: Fantasy races cost more depending on how different they are and how strange they are for the setting. In an otherwise normal world setting, a lone Elder Thing -- a primordial, radially symmetric being -- character would cost so much to almost certainly be regarded as a WHAT. In a setting where the Elder Things have risen from hibernation and small enclaves are known to live among humans, significantly less -- probably less than a much more human-like Elf who isn't germane to the setting! Once you take human, ethnicity may be a question and that depends entirely on your setting. To use M:tG for an example, "Caucasian" costs very little on Innistrad, far more in Jammura, and as much as a foriegn species on Tarkir. In essence, your setting determines the amount of focus a particular set of genetics would take.

For readership, take Sex, Gender, and Sexuality for examples -- assuming we've already picked human or near-human Nonhumans might have some of these costs rolled into their species cost instead. Male and Female are pretty low impact, because most of your readership is probably one and is familiar with the other. Other, less familiar choices cost more depending on how much they are likely to vary from a familiar experience and how specific and detailed you want to be, and they cost even MORE if you're referring to biological sex, since an 'other' choice there is going to be even less familiar and require even more focus to include well. Sexuality is generally a pretty low-impact choice: Straight and gay are cheap, bi and asexual still affordable, and other options harder but still feasible -- after all, it shouldn't come up unless romantic entanglements of some sort are an included matter, and then focusing on those whats of a character (or rather, those wants) is kind of the point.

And again, there is NOTHING wrong with high-cost choices. In any character, you can take some and still make the character a Who. In any story, you can take some and still have your cast be a cast and not a checklist. And having every character being mostly the same WHATS can get uninteresting real fast. And the more skilled you are as a writer, the more of a "budget" you can get. At this point I'd like to give a tip of my hat to something that does Diversity well: the webcomic Blingsprings. Blindsprings, among many colorful characters, features Ember and Harris... and over the story it becomes clear that both of them have quite a lot of WHAT, both earthly WHAT and magical WHAT, but neither of them was ever presented as anything but WHO first and foremost, and that's a mark of good writing. In particluar, I remember an "Annotation" page that "revealed" Ember was nonbinary. At first the page annoyed me, not because of the facts (Ember is Ember, that's what matters) but because it seemed to be treated as a WHAT that would eclipse the WHO, and that's not something I wanted to happen. My fears were misplaced -- the character is firmly a WHO and the page serves to explain why none of the characters in the story were particularly concerned with the WHAT The way normal, flawed people of our world might be (and it's not, as it too often is in fiction that reaches deep into diversity, because the characters are "better, more accepting people" or any of that drivel. It's because there's a well thought-out background of the setting, culture-shaping interactions with genderless spirits, that changes how they see the topic, and how they naturally would see the topic.

It's certainly nice to see, but not every story needs or wants to be that, and paying more diversity costs would be unimportant, or just plain distracting from what the characters do, rather than who they are underneath, defining them. Know your story, know your ability, and write characters. Because in the end a good character is a good character as a he, a she, a little of both, a lot of neither, or even an Elder Thing.