
Toilet seat! Keep any shavings (beard & otherwise) cleaned up. Might want to get a Costco card for the apartment. Create a kitty that everyone pays into for toilet paper and cleaning supplies. Make a weekly chore rota. Decide the level of acceptable casual undress for the apartment as a group (not everyone is comfortable with boxers/bra & panties in the apartment.) Have a white board calendar where everyone puts plans/friend invites.
I figured, and it’s silly but just having lived with people then counting toilet rolls and ending up bringing my own roll into the bathroom because I was the only one replacing any didn’t help in my experience, if everyone paid in and more than enough got bought I think we’d have gotten along better. And everyone’s more likely to clean if the supplies are already bought and they don’t have to buy them, plus if anyone doesn’t like a certain scent or something then it doesn’t get bought at all.