A way of worshipping Lord Shiva is through the Shivling, or the Shivlingam. It is neither a statue nor a photograph, but a symbolic representation of his presence in the form of a smooth, black stone with a rounded top.
People worship a Shivling through Abhishekam rituals where they pour milk, water, curd, sandalwood, and more on Lord Shiva in order to receive his blessings.

But in between this, there was a devotee of Lord Shiva who worshipped the Shivling not with milk or curd, but rather with meat, water, and the likes.