Mostly it's as I go, besides the general direction of the story if that makes sense. I have a few different endings I'm trying to target as well as some core events I planned out at the beginning of this whole thing, scrapped a few, but overall it's pretty much planned for the overarching plot. Not so much for character events and such, I make those on the fly so they feel more natural and not forced. Like Fae was gonna be a "femdom" personality but once I wrote out the first "bro" it just felt perfect for her to be a bro dude and spiral into that sibling thing to hit that audience
I plan out the upcoming chapter in advance while working on the previous chapter so I can make them "connect", but I don't start dialogue work on the upcoming chapter until I release the version I'm working on. So once the previous update is out, I start writing in dialogue to hit all the key points, if it's too short I'll add new stuff- like Raven wasn't really planned but we needed a store for something filler I added in Ch5 since it felt too short. A little mad at myself for it, I think her introduction pushed me past my limit of characters I can properly support but that's tomorrow's problem
I just made my most advanced animated scene yesterday with 3 moving parts and 3 separate connecting scenes that follow as an ongoing "date"- focused purely on feet. And more stuff in progress