Where would I start with making a custom skin for madeline?

[eternal niche]

I want to make a custom skin for madeline but i dont know:
What do do after spriting it
What (if anything) to do before starting to sprite
Literally anything else

[lunar tendon]

you probably should read https://github.com/AAA1459/SkinModHelper/blob/dev/docs/guide/README.md

[jovial urchin]

https://kuksattu.github.io/Celeste/SkinModTemplate/

this is a really helpful skin mod template put together by kuksa

it should be mostly set up in the way Skin Mod Helper needs it to be, you just need to update file names and paths etc. and replace the images with your sprites