john making arthur moisturize their hands because he doesn't like how dry and cracked they usually feel. plus it makes their hands prettier

john also picks at his own nails+skin a lot. he does NOT like when they have to use hand sanitizer. also sometimes they have to put on gloves and he really really hates how constricting they feel but really loves how they look so it evens out enough. he still complains tho

when they write john is usually the one to write, obviously, but sometimes arthur likes to write down things too and john just tells him where to move his hand. its silly, but he didnt realize he missed writing so much until he didnt do it anymore. they keep a little journal (john does NOT want it to be called a diary. not even cus 'diary is a girl word' or whatever greg heffley said, but because the word doesn't fit and he doesn't want people to think they're writing about diary stuff. kayne calls it a diary anyways.) nobody else really knows about the journal, its kind of a personal thing, but i think there could be some fun scenarios with characters like the butcher reading their journal and seeing them talk about past experiences they would never give up to him otherwise, like mister faust :3 maybe he could even use it against them. or maybe he'd just become more infatuated with arthur i mean interested haha oh wait that sounds romantic too. obsessed but DEFINITELY not in a gay way. yeah that one'll convince em

i could also see them collecting small things, like maybe a wrapper from something they ate that day but meant more to them than just food(like a childhood food arthur hasn't had in a long time), and kinda scrap booking it in the journal. they don't bother to make it pretty, the only person that will ever actually be seeing it is john, but it means a lot to them to have a little collection of smaller but meaningful memories. it helps them both, with reassuring arthur he's not crazy even though he rarely has doubts about that, and helping john a LOT more with reassuring him his memory is fine now and he isnt forgetting or misremembering anything.