Also on these boards
every Thanksgiving when my mom bought mixed nuts for the coffee table, I would save all the perfectly halved walnuts. Later, I would write tiny little notes to her or friends from college or place itty-bitty treasures inside and leave them to be found. ;)
Ages ago I saw something like this in a Victoria magazine (former, not current incarnation). It was lovely and elegant, less busy but basically the same concept. Easy to do, too.