Here’s a letter by Srila Prabhupada to his disciple Laksmimoni in May 1971 instructing about deity worship.
Please accept my blessings. I am in due receipt of your letter dated 21st April, 1971 as well as the photos of the altar and your fine looking Vaisnava son, sent by separate post. If he grows more teeth you will have to supply him more prasadam. That’s nice. And he is such a fortunate child. From the very beginning he is having association with devotees, when he was 6 months old he chose Bhagavatam. So take care of him nicely and raise him a Krishna Conscious child and be blessed with your good husband and child and Lord Jagannath, and be full of transcendental bliss.
So far as taking care of the Deities and your family simultaneously, you have to do both mutually, but the main importance is Deity worship. Just like a busy housewife always busy in household affairs, yet still she is engaged in dressing herself nicely, combing her hair, etc. So both things go together.
Yes, at least once daily the Deity’s clothes must be changed, in the morning. If the Deities are small, as they appear to be from the photograph, then they can be laid down in a bed at night. And they can be given nightgowns to wear before taking rest. That is nice. If there is time and facility then these things can be implemented. So far as bathing is concerned, it requires two hands and one tongue. In your left hand be ringing a bell and simultaneously with your right hand pour water. Chant Hare Krishna, Cintamani, Govinda Jaya Jaya, etc., like that.
So far as touching the Deity, this is possible only in a big temple with big Deities, not in a small temple. In big temples like Jagannath Puri the devotees circumambulate and sometimes touch the Lotus Feet of the Lord, but in a small temple that is not possible. If you need help in caring for Tulsi devi, you can write Govinda Dasi in Hawaii for instruction.
Deity worship can be learned at not less than ten years by children. Before that they can assist. They can learn how to bow down, how to dance and chant, how to make garlands, clean arati utensils, etc. In this way they can be engaged. These are also different parts of Deity worship.
Regarding Satyaloka, one is in the material world and one is in the spiritual world. The spiritual Satyaloka is eternal; the material Satyaloka is not, although it is so-called. Satyaloka is another name for Vaikuntha.
Hoping this will meet you in good health and jolly in Krishna’s service.
Your ever well-wisher,
A.C. Bhaktivedanta Swami