Here is a simple and traditional slok you can recite before the Shantinath idol, along with its meaning.

Slok (Navkar Mantra) to recite before any Tirthankar idol, including Shantinath: Namaḥ Arihāṇam, Namaḥ Siddhāṁ, Namaḥ Ṇaṁrakā Bhāve, Namōo Loḍhāyā, Namō Mahāvasāyā.

Meaning (arth) in Jain tradition:

• Namo Arihāṇāya: I bow to the Arihants (the perfected beings who have conquered inner enemies).
• Namo Siddhāyāya: I bow to the Siddhas (the liberated souls).
• Namo ṇaṁrakāya Bhāve: I bow to the Śaddhākhyas/Āchāryas and to the spiritual teachers who reveal right conduct and knowledge.
• Namo Loḍhāyā: I bow to the Upadhyāyas and the Jain Sangha who guide practice.
• Namo Mahāvasāyā: I bow to the great ones who have achieved omniscience and liberation.

Notes:

• This Navkar Mantra is a foundational, universal prayer and is commonly recited before worship of any Tirthankar idol, including Shantinath. It centers the mind on right faith, right knowledge, and right conduct as you begin the worship.
• Different Jain traditions (Digambar and Śvetāmbara) may have small variations in pronunciation or in accompanying verses used during Snatra Puja. The essential spirit—humility, aspiration for purification, and reverence before the Tirthankar—remains the same.

If you want a Shantinath-specific opening prayer or chaitya vandan for Snatra Puja, you can look at a Snatra Puja guide for temple procedures and verses used for Shantinath; see this discussion for context: .