Steenz and Camilla Zhang made a comic script template (based on feedback from folks in industry)
https://www.oheysteenz.com/scs-template or at https://www.camillazhang.com/standard-comic-script
When I wrote mine I adapted it from Fred Van Lente
https://www.creatorresource.com/anatomy-of-a-comic-script/
Mine ended up being pretty similar to what they have above! Considering all the stakeholders that have to use the thing.
When I make my own comics I don't write a script like this at all.
I half write and then move into thumbnail, write as I thumbnail, thumbnail and then write...it's a mess 🤣
A well done script is a great communication tool for everyone involved. What stuck out to me was to make the dialogue easy to copy paste for the letterer. I suppose I've also been in the role of doing all those things (editor, writer, designer, letterer, etc.) so I can also think about what direction I would want.