For the tumblr thingy (I don't know if it's still going) how about the froggettes?
kind of posts they reblog: music and occasionally aesthetics/moodboards
first person they followed: the rockers; they found them when the froggettes were looking through the music tag
theme: they would most definitely have a music player, and the theme would probably have some form of rock’n’roll aesthetic, and somehow the color pallette would look good, despite having green, blue and pink
what kind of posts they make at 2 am: chances are, if the froggettes are up at 2 am, they’re probably doing a late-night performance, and they’d be liveblogging the whole preparation for said performance