Students at Hogwarts had to carry their millions of textbooks somewhere, right? I always imagined them carrying around messenger bags/satchels, while my friend TheAmazingMaddy pictured them using backpack. But obviously, you have to customize your backpack, so these are some of the ways that Hogwarts students could have done this, courtesy of TheAmazingMaddy who is, in fact, amazing :)
(I'm just quoting what Maddy wrote here): "I imagined Wizard themed backpacks! A Weird Sisters one, a Quidditch One, one for each Hogwarts House, and we all know someone has got a Celestina Warbeck one."
Moi: Mrs. Weasley definitely had a Celestina Warbeck bag, and I bet 7 Galleons that Ginny had a Holyhead Harpies bag, and Harry had a gross hand-me-down backpack from Dudley.
Maddy: Ginny totally had a Holyhead Harpies backpack. Harry refuses to get a different backpack though, because he kinda likes the grim little bag, because it was the first thing he ever got from his cousin that wasn't clothes, and in first year, Hermione and Ron help him to decorate his grim little bag with pins. So no one questioned the gigantic CHUDLEY CANNONS pin right in the middle of his bag. Hermione's bookbag is all black, but she has a couple pins on it, such as one with the cover of Maltida, and other classic muggle literature we know she's read. Ron's bookbag is a Chudley Cannons one.
Matilda is definitely Hermione from a different universe.