On this day of Ekadashi one must perform due respects and poojan to the Almighty Supreme God with fresh flowers and Tulsi leaves. One must keep a divo (holy candle) in front of God and sing His praise with great joy and perform continuous devotion. During the night, one should perform jagran, sing bhajans, kirtans and chant the name of Bhagwan Supreme.
Kamika Ekadashi falls on the eleventh day of the dark fortnight (Krishna Paksha) of the month of Shravan. This Ekadashi is described in detail in the Brahma Vaivarta Purana, where Lord Krishna narrates its glory to King Yudhishthira.
The Lord explains that the merit of observing Kamika Ekadashi surpasses all forms of charity and sacrifice. Even the great act of donating the earth itself, adorned with gold, cannot match the spiritual benefit of observing this Ekadashi with full devotion.
Tulsi leaves hold special importance on this day. Offering Tulsi to Lord Vishnu on Kamika Ekadashi is said to purify the devotee of all sins accumulated over many lifetimes. Devotees are also encouraged to avoid eating rice on all Ekadashis, but particularly on Kamika, as the scriptures describe how the soul of a rice grain is associated with the departed.