Leave the dhying foliage on the plants as long as possible until the leaves are completely yellow/brown. Some folks gather the dying leaves, fold them in half and then rubberband them so they don't look as messy. Once they have died completely you can either cut or pull them off. The reason why you leave them on the plant as long as possible is that the bulbs are storing nutrients so they can bloom again next year as the leaves die.
lod lEAVE THE DYING FOLIAGE ON THE PLANT AS LONG AS POSSIBLE. wHEN IT TURNS COMPLETELY YELLOW/BROWN YOU