@Revekah0 The best way to make a shared bathroom work is to provide each guest a dedicated storage compartment for their personal toiletries. That way, their stuff is at hand when they need it but it's not cluttering the room.
Same goes for the kitchen - guests appreciate having a dedicated basket or shelf in the pantry. It's also great if you can do that with the fridge, but if that's not possible, you can offer stickers or labels to mark their goods.