Work from the finished puzzle. Slide a sheet of paper under one bag's region at a time and lift it off whole. The coloured borders follow real piece seams, so nothing needs cutting.
Put the card in the bag. Each bag card above has a small map showing where that bag sits. Write the number on the bag, or slip a sketch of the map inside.
Order matters. With "Each bag joins an earlier one", every new bag attaches to something already built, so there's never a floating island. Random order makes it more of a mystery.