The subject is homophobia in science fiction, and how to counteract (in a small way) this by improving the positive representation of LGBT characters in our writing. I believe there are several approaches we can take, and that a combination of these would be the best way to achieve what we're aiming for. I certainly don't think that any of these are better than others, or that everybody should try to use them all, nor that everybody should try to do something like this in all of their fiction. But they're ideas to try, and they might help.
- Write science fiction about explicitly LGBT themes: write queer and trans protagonists, not just as positive characters, but as an intrinsic part of the futuristic universe you're creating. Write stories about homophobia as well, and about other issues that LGBT people face; challenge your readers. Make a difference by reminding everyone that the world is ugly that we would wish.
- Write stories in which queer and trans protagonists are treated just like anybody else, where they don't even have to be pointed out because in the Utopian world you're creating no one thinks about them any differently; just like people with black hair. Show what we would like the world to be, what we think is possible with more tolerance and acceptance.
- If you don't want to do either of the above in a particular story, because it's a story about something else, not about LGBT issues, then just people your story with a representative sample of sexes, races, sexualities and abilities (just as real life is so populated). This can include:
- Protagonists/Viewpoint characters: if you start writing your story with the knowledge that your protag is queer (or whatever), even if you don't make a big deal out of it, it should, if you're a good writer, change the way that character works in some small ways. It may make her/him more careful in certain company, more comfortable around the opposite sex, have subtly different reactions to various stimuli or conversations (all of these non-sexual). Just having a positive queer viewpoint character is useful helps to redress the balance.
- Minor characters/walk-ons: the same is true as with protags, a minor character may come across slightly differently if you've chosen to write them as gay. But even if they don't, if they're too minor and walk-on for that, just having a few queer characters in the background makes your world more representative and realistic (and LGBT-positive).
- Write about a universe or an alien planet with radically different sex/ gender/ partnership/ reproductive alignments than the cis-heteronormative world we normally see. This is what Ursula Le Guin does in her best writing, and why science fiction is great for questioning the norms most people take for granted.