So, I want to write a noncon fic between a futa and a cis girl. For context, futa is a yandere and goes insane, but still treats the girl gently.

I want to make the fic hot for people who enjoy noncon, but I've never written stuff like that before. Any advice would be appreciated!

Kinda a mix of both. It's for a game called "Degrees of Lewdity", which allows you to make your own customizable character. A character named Robin is the cis girl in the fic, and the futa is my character named Yui.
(Also this is my first time replying to another comment so I apologize if I'm doing it wrong)

If you don't want to go full rape, Eventual_consent is your friend. Is it a 3rd or first person account?

3rd person!

A tip I have for any writer is always have a thesis, a summary sentence or paragraph, to state what the point of whatever it is you’re talking about. More broadly it applies to exposition over narrative but the thesis is key, that would be whatever the conflict/resolution is. Don’t settle for the first draft either; be willing to rewrite potions that don’t exactly work smoothly. Don’t be afraid of the thesaurus either, because that can be especially useful to keep your dialogue as diverse as possible.