What are/Where can I find some good tips/tutorials for NSFW modelling?

Some assets (rigged and textured characters, mostly) can be found at https://smutba.se/ , a fairly Blender-centric site where a few prolific 3D porn artists publish their characters’ setups for others to play with and learn from. It has an associated Discord, too.

(Even if they use popular game characters, often the bodies aren’t original game assets but custom jobs with a head transplant)