Somebody is moving, and there's a last day coming, and you'd like to put something in their hands that isn't a keyring. These are the books people give at that moment: the one about the invisible string of love that stretches however far the car drives, the raccoon whose mother folds a kiss into his palm before he leaves his tree, the boy who flatly refuses to go and complains about it for thirty glorious pages. Pick the single one that suits the child and the day, sign the front, and hand it over.
Any single one here does the whole job, so you're choosing one to give. What they have in common is that they're written for the week of a move. Sort them like this. If the child is the one leaving and they're small, 'A Kiss Goodbye' and 'Goodbye House' are the tender ones for the actual last day. If they're small and mostly just anxious about the far end, 'The Berenstain Bears' Moving Day' is the easiest thing here and ends with the neighbors at the door carrying food. If they're leaving and they're angry about it, 'Alexander, Who's Not (Do You Hear Me? I Mean It!) Going to Move' is on their side and nobody else's. For a child around eight to eleven, 'Allie Finkle's Rules for Girls: Moving Day' is a funny novel with real friendship trouble in it. And 'The Invisible String' is the one that works no matter which end of the goodbye the child is standing on, which is why it's first. On the keepsake question: 'The Invisible String', 'A Kiss Goodbye' and the Berenstain one all have room and reason to be signed, and a book with a friend's handwriting inside the cover outlives the friendship it came from.