Temple Room Etiquette
Temple room etiquette is described in detail by Srila Prabhupada in his Nectar of Devotion.
Other Quotes from Srila Prabhupada
Another thing I request is that everything in the Temple should be kept nice and clean. Everyone should wash hands before touching anything of Krsna's. We should always remember that Krsna is the purest and similarly only the purest can associate with Him. Cleanliness is next to Godliness.
SP letter to Nandarani and Krsna Devi (October 4, 1967)
[In arcana] There is no matter if there is a little change here and there-the real duty is love and devotion.
SP letter to Yamuna (July 26, 1970)
Regarding the prasadam, I never approved Mr. Malkani cooking in the temple. He is not initiated. Of course, he is Hindu, but he is not initiated to cook in the temple. Any paid cook is not desirable. The independent cooking in the temple is not good." [Footnote: "The right thing is that only twice initiated brahmin disciples cook in the temple."]
SP letter to Kirtanananda (November 23, 1974)
Yes, a non-initiate can work under the direction of a devotee in the kitchen.
SP letter to Mahapurusa (March 28, 1968)
It is customary for the priests of temples in India not even to touch outsiders nor enter the Deity room after having been touched. This is a very important item in temple worship. CC. Antya 4.128 purport
Seeing the Deity in a Pleasing Mood
You have described Their Lordships Sri Sri Radha Krsna at London Temple as wonderful. Yes, that is the test of standard service. If we see the Deities in very pleasing mood, that will certify our service unto the Lord. So everywhere we shall see the Deities in such pleasing mood. As soon as we see the Deities in a different mood we must immediately understand our discrepancies.
SP letter to Tamala Krsna (May 27, 1970)
Srila Prabhupada said that the devotional practices in the Jaipur temple were standard and could be introduced throughout ISKCON. [i.e. offering scented oils on cotton-tipped sticks, which the priest would later offer, along with the flower garland from the deities, to the incoming worshipers in exchange for fresh garlands]
Lilamrta Volume V p. 47-8