My world has a lot of characters who are genderless, who choose their gender (or can randomly change on a whim for whatever reason, and some flip back and forth often.) Using they/them pronouns is really easy if you just practice a little. If you think about it, you use they/them automatically already, in situations when you don't know a person's gender. For example: See that person in the hoodie across the street? They just dropped their wallet. They/their just pops out of your mouth without thinking about it. There's no need to switch from "they" to "it" (unless it's, like, a non-human monster or creature.