A thing I'd like to throw my advice here to as a trans person. As much as a good point of it is to make it feels like the aspect of being trans is no big deal: at the same time, you don't want it to just be tacked on. Being trans is also an important aspect of a trans person. It's what shapes our lives and the way we view society (and by extension how society views us.) You don't have to go to overt ways of doing it, especially if your comic isn't focusing too much on anything LGBT+. If you're looking for ways to show your characters are trans, with a trans guy if he does get top surgery that's usually a way to see it. And as someone said before, you can usually have the characters seen taking their respective HRT. As well as the way characters can talk about experiences, especially for trans people growing up to be socialized as the gender they aren't. Whether or not it's a sore subject, or if that character is absolutely fine with talking about it. There's also the aspect of whether or not your characters are stealth or open about it.
There is also another thing, that trans people are extremely diverse and some may not even want to go what people believe is "the full on end" of it. Some trans men keep their chest, some trans women never get bottom surgery. Whether these options happen because of lack of access, or specifically because they don't want to, those are options you can consider. Also with dysphoria, not every trans person experiences it. And dysphoria can come in many different flavors. Sometimes trans people are dysphoric about specific things, but not others. Like, if a trans person is dysphoric about their chest but not interested in bottom surgery. Or whether or not they are or aren't fine with the way their voice sounds.
I'd recommend just being open to feedback the more you write these characters. In the end, every trans experience is different, and your characters are experiencing one specific to them. You don't have to include every single aspect about it.
