Your chalice represents the element of water. It represents the Holy Mother and the womb of all life.
In addition to libations, you can use your chalice as a method of blessing something If you put salt water, or some other sacred potion into your chalice, you do so to bless it so that everything that is touched by that water or potion is blessed by it.
You can use waters and potions to bring about specific energies by learning the correspondences of different plants, flowers, fruits, etc
Your chalice can be ANY kind of cup you desire (even a coffee mug if you are needing to be very private with your practice).
You can learn how to consecrate your sacred chalice by taking my free 18-week audio course, A Witch's Primer.