So, how exactly do you make one part of a costume ghost? I can't seem to see any sort of button, when editing the costume, but I know that it's possible…am I just totally blind?
Do you kinda get what i'm trying to say?
I'm gonna re-explain:
So when i'm editing a costume, say I wanted the hair to be ghost, what would I do, without making it a separate costume and adding:

set [ghost v] effect to (25) 

?

I would 100% appreciate help!

See the Scratch Wiki article.

do you mean making a part of a costume transparent in the costume editor? you can do that by getting some vector editing program and doing it there. unfortunately, scratch's editor is very restricted.