if they are in the ground then just leaving them alone. if they are in pots then lift them and plant in good compost in a slightly larger pot than the root ball. then keep them watered and in a sheltered spot.

We lift ours and plant them in a big clump in a cool, moist shady part of the garden. They should die down then reappear in autumn or spring depending on variety

Yes it depends on the variety. I lift mine then split them up into single plants, they come apart easily with roots on the plantlets. Then re-plant either in the ground or in pots. I have also read somewhere that the leaves can be cut across to reduce the plant and it will start growing from the centre.