Observe the overall shape
Check the color and surface texture
Look for natural spiral patterns
Identify visible chakra marks
Note the number of openings or pores
Examine the presence...
Decide the type of fast you will observe: nirjala, phalahar, or partial fast
Eat a light, sattvic meal before sunset on the previous day
Avoid onion,...
Bathe and wear clean clothes before worship
Clean the पूजा area and place a picture or Shiva Lingam
Light a lamp and incense
Offer water, milk, honey,...