The first image that comes to mind when one thinks about Shiva is the Shivling and the Snakes around the neck of Shiva. We tremble with fear on encountering a snake. So imagine using snake as a garland. To attain bliss we have to be fearless. We have to drop the fear of tomorrow, fear of losing social status, fear of losing wealth, fear of losing family members, fear of death, and fear of all that is fleeting… When all fear is dropped, we drop ignorance. This leads to bliss. The snakes on Shiva extols this truth. The snake is the fear of the world and future. He who can make snake (fear) a garland attains bliss.
What is bliss? It is the realization of the Supreme Truth in all animate and inanimate. That there is no second. It has to be attained here not in any other place. When this is realized - one escapes from all fears and pains.
What is Shivling? It is a symbol of the fiery seed responsible for all forms of creation in the world – which we know and of which we have no knowledge - creation is endless. We are here because of that primordial column of fire. And we return back to That - the only source. Shivling makes our path to self realization easy. Constant meditation on it removes ignorance and a day will come when we will not even need the Shivling. All forms will drop and we will merge in the formless. Shiva is the formless truth. The form (Shivling) is a boat to carry us from the shores of ignorance to the space of bliss.