At its best:
Carefully remove the snowdrops from their pots, being careful not to disturb the soil, and place inside your clay pots (add potting compost first, if necessary).
Once your snowdrops are in the pot, top off the soil with moss, aiming to cover any bare compost. You only need a little, so don't collect much.
To settle your snowdrops in, give the pot a good watering. Place it where you can enjoy the delicate, nodding blooms.