Hey, I’m sorry it’s taken me such a long time to respond. I had another health issue crop up and that ended up making my RSIs worse and it was all a bit of a mess that sapped most of my spare capacity for a while. I’m getting things a bit more under control now and I’ve got some good voice typing software so hopefully this is better late than never. (Sorry for reviving an older topic mods.)
Include disabled characters, preferably multiple. There are a lot of disabled people in the real world, probably more than you think. I don’t recall the exact statistic but it’s something like one in five people are disabled. So if you have a cast of a dozen or more characters, having a couple of disabled characters in the mix is actually quite realistic and it makes it much easier to avoid token representation and some negative tropes. They don’t all need to be main characters by any means, though it helps if they’re not *all* extremely minor characters.
Avoid bad tropes. Pretty simple, but it is worth noting that many tropes are mostly bad because of being overused/predominant. For example: if the only disabled character in your story is a villain that’s bad. But if you have a number of disabled characters and one of them is a villain (and they aren’t a villain *because of* their disability) that’s fine. Just try to avoid connecting physical abnormality to villainy. We should have disabled villains on occasion, the issue is in linking disability to villainy and in using it as a shorthand for villainy.
Following on from that thought; disabled characters should appear in all sorts of different roles and positions, as we do in real life. There are, of a certainty, some occupations/roles/actions that certain disabilities make extremely hard. But just as often the reason a disabled person can’t do something is more down to a lack of accessibility and accommodations (or people just assuming that a disabled person couldn't do it and not giving them the opportunity). A very simple example relevant to the current times: right up through early 2020 many disabled people were refused jobs or positions studying because they would need to work/study from home much of the time and many employers and universities/colleges/schools said that wasn’t possible. I.e. they weren’t willing to bother dealing with it. (There are legal rights about accessibility in many places but they are often ignored. And fighting for them often takes money and energy that many disabled people don't have.) Then the pandemic starts and suddenly these “impossible” accommodations are commonplace because nondisabled people needed them. And you can be certain many of these places will go right back to considering such accommodations impossible as the pandemic wanes. (There’s an extensive rabbit hole here about how disabled people have been ignored, left behind, and otherwise severely impacted by the pandemic (including being refused treatment based on “quality of life”/perceived value and such). But that is a whole other topic and I've already gone on enough of a tangent.)
Read about disability representation and the experiences of disabled people. There are a bunch of resources out there that go into a lot more depth than I have about representation. And if you’re writing about a character with a specific disability there are plenty of people who have written about their experiences with that disability. Even as a disabled person I have a lot to learn if I want to write characters with other disabilities well.
Get feedback/get disabled people involved. If you’re writing a book, having disabled alpha/beta readers is extremely helpful, as can be disability consultants. For a film or TV show you really want to have disabled people involved in the production and, crucially, to listen to what they have to say. So disabled writers/consultants/actors/etc. I don’t remember the exact numbers but the proportion of characters in American film and TV who are disabled is a fraction of the ~20%+ proportion of people who are disabled in real life. And of the characters who are disabled somewhere in the region of 5% are actually played by disabled actors. Seriously. That number might have improved a little bit now but it’s still ridiculously low. Also “fun” is seeing how many nondisabled actors win awards for playing disabled characters. Just because they won an award for it doesn’t necessarily mean their portrayal was accurate or positive. It means they did a great job of portraying how the critics and a lot of the general audience like to see disabled people in film/tv. Which means even if the performance was good, often the surrounding story and themes were quite problematic.
Just doing 1 and 2, including disabled characters and avoiding the negative tropes, is sadly enough to be well above average. But it isn’t hard to do a lot better if you put some effort into doing so.
I hope that’s of some use, late as it is.