In Mount Kailash during the Pradosha pooja, the devas and hermits and shiv-bhakts gathered together, chanted vedas and propitiated Lord Shiva. The chant of “Har Har Mahadeo” rents the air during the Pradosha pooja. Nandikeshwarar, the bull-god, is also propitiated during Pradosha.
It is important for every Hindu to visit a shivalaya (or a temple of Lord Shiva) at least during the days when there Pradosha. This day is special as there as special poojas, archanas and aradhanas for Lord Shiva alias Umamaheswarar, Goddess Uma Parvathi and Nandikeshwarar. The “deeparadhana” during Pradosha is so riveting that it helps in cleansing your soul.
The Pradosha time period falls between 4:30 pm and 6:00 pm. It happens every fortnight.
What can you offer for abhishekams during Pradosha?
Milk, Curd, Rice flour, Ghee, Butter, Arugampul (a type of grass that is generally offered to Lord Ganesha), Sandalwood powder and Vermilion powder. 
When you take active part in Pradosha pooja, we can not only fulfil all our desires but we will also be free of the sins that we may have willingly or unwillingly committed. No negativity can sustain in front of the positive energy emanated during Pradosha pooja.
Why should you visit temples?
All of us know the famous Tamil maxim – “ Alayam chelvathu chala chirandathu.
The Brahmakumaris claim that when a person visits a temple, he invariably is seeking benefits for himself. When there are so many people visiting a temple, there is a cumulative positive energy that is generated. It is this energy that helps alleviate one’s sufferings, physical and mental agony. There can be no negative energy in a temple. So, as our ancestors have told us – any temple that we visit can cleanse our mind and soul if we make visiting temples a regular habit.
Offering milk, curd, tender coconut water, panchamrutham to Lord Shiva will ensure that the Lord bestows our wishes. When the devars had a problem, they first appealed to Nandikeshwara who then passed on the message to Lord Shiva. Therefore during Pradosha, it is important to pray to Lord Nandikeshwara.
People with rishabh lagnam in their horoscope and those whose stars are Karthikai, Rohini, Mirgaseersham should definitely pray to Lord Nandikeshwara. The meaning of Rishabh is “bull” and this signifies the bull god. There is a bull temple at Basavanagudi at Bangalore.
Pradosham is very special because it is during this time that Lord Shiva drank the poison and because his kanth (neck) became blue, he is called as “neelakantan” or “neelakanta siva”.  
Praying to Lord Shiva during Pradosha will protect us from Rahu, Ketu. Fasting on days of Pradosha is highly beneficial. Whatever we desire will definitely get fulfilled.
Lord Shiva had consumed the poison on a Saturday therefore “shanipradosham” is absolutely special. This is the reason why “shanipradosham” is called as “mahapradosham”.
The dosha period is the twilight period. The right time to pray to Lord Shiva is this twilight period.  Om Namah Shivaya Shivaya Namaha….. this chant is more than enough. Or you can chant the Maha mritunjaya mantra…
“Pra” means “ excess”, “Dosha” refers to negativity. Therefore, “Pradosha” signifies extreme negativity and during this period as Lord Shiva consumed poison to protect his devotees, it is important for us to pray to Lord Shiva and seek his blessings.