The Hindu traditions celebrate gods and goddesses with the use of sacred images., which inspire human spiritual imagination. Shiva Lingam is a black fossil stone used to perform puja ---meditation -- to the god of creation and destruction, Lord Shiva, according to the website, Devasthanam. (See References 1) Use Shiva Lingam as aids in Shiva worship, in meditation and as energy-clearing tools.
Perform sacred bathing, called abhishek, as form of Shiva worship. Bathing the lingam by pouring milk and water or yoghurt, ghee and honey over the stone is recommended by Devasthanam. (See References 1)
One can also clear energy and align chakras with a Shiva Lingam. Place the stone on different chakras to address different symptoms of energy blockage, suggests the website, Healing Crystals for You! Lay a Shiva Lingam on your heart chakra to promote connection with the Divine Mind and to inspire forgiveness for the things that keep you separated from others. (See References 2) Practice meditation with a Shiva Lingam on your third eye chakra to instil a sense of what you bring to life that nobody else offers.
Perform puja -- worship -- to Shiva Lingam. Offer your worship to the feet of the Lord Shiva by committing your entire being and all of your thoughts and actions to God. Chants Shiva's and your guru's name so the light of your guru's being and the light of Lord Shiva can merge. (See References 3)