Nadi-puja is a form of Guru-puja for aughar and darshani

This is the most famous puja in Natha Sampradaya. It takes only 1-2 minutes. It can be described as a short ritual for honoring a deity or Guru, which is practiced by a sadhak in the line of nathas. The ritual is performed twice a day - in the morning and evening. By doing so he is building a spiritual channel that connects the sadhak with the parampara of Teachers which is highly beneficial for saddhana. 

Nath-aughar performs puja almost in the same manner as jigyasu performs Shambhavi-puja except that he holds a nadi (whistle) in his right hand and after pronouncing the mantra he brings the nadi to his mouth and whistles. After that his right hand goes back down and he bows. After 3 bows with a sound, he performs a rotation. Thus holding the elbow of the right hand which holds the whistle by the mouth with the left hand, Nath makes a sound called dhvani spreading it to the 8 parts of the world. This way he honors all Deities in the Universe. 

Puja for Nathas-darshani looks the same except they also touch the kundalas in their ears with both hands as well as a paduk of their Guru and Deities. Darshani can just touch their kundalas, nadi-djaneu is not mandatory.