Mental Worship of Shiva – Shiva Purana

In the chapter 8 in Section 5 of Kailash-saṃhita of Shiva Purana, Shiva informed about mental worship of Shiva.
There are five Avaraṇas here. These are:

1. The five Brahmans shall be worshipped in order in the north-east, east, south, north and west. The devotee shall worship the eye and Astra in the southeast, northeast, southwest, northwest and in the middle. He shall worship Ananta in the petal in the east; the Sukṣma in the South; Sivottama in the west; Ekanetra in the north; Ekarudra in the northeast; the Trinity in the southeast; Srikaṇṭha in the south-west and Sikhaṇḍisha in the north-west.
2. He shall worship the emperors.
3. The devotee shall worship Vṛṣeshnna in the middle of the eastern door. Nandi shall be worshipped to the south and Mahakala to the north of it, Bhṛngisha to the west of the southern door. Vinayaka shall be worshipped in the square to the cast of that with scents; Vrsabha in the northwest and Guha in the southern square. To the east of the northern door the following eight shall be worshipped in accordance with the rules of circumambulation. They are Bhava, Sarva, Ishana, Rudra, Pashupati, Ugra, Bhima and Mahadeva. Such is the worship in the third Avarana.
4. After invoking Lord Shiva with the mantra “Yo Vedadau Svaraḥ” he shall worship him in the lotus above the pericarp in the east. He shall worship Lord Shiva in the eastern, Visvesa in the southern, Parameshana in the northern and Sarvesha in the western petal. He shall worship Rudra in the south after invoking him with Ṛk “A vo rajanam” in the petals and the pericarp with scents, flowers etc. Shiva shall be worshipped in the east; Hara in the south; Mṛda in the north and Bhava in the petal in the western quarter. They shall be worshipped in this order. After invoking Viṣṇu by uttering the mantra “Pra tad Vishnu” etc. he shall worship him in the north on the pericarp and the petals with scents, flowers etc. He shall worship Vasudeva in the east; Aniruddha in the south; Saṃkarṣaṇa in the north and Pradyumna in the west. The knower of Mantras shall invoke Brahma with the mantra “Hiraṇyagarbhaḥ Samavartata” etc. and worship him in the lotus to the west. He shall worship Hiraṇyagarbha in the cast; Viraja in the south; Puṣkara in the north and Kala in the west.

 
In the topmost row the Lokapalas shall be worshipped in different spots beginning with the last and proceeding in the manner of circumambulation. The following ten are the Bijas for the Lokapalas: —Ranta (ending with ‘Ra’), Panta (ending with ‘Pa’), Jnanta (ending with ‘Jna’), Lanta (ending with ‘La’) twice, Apurvaka (beginning with ‘A’), Ṣanta (ending with ‘Ṣa’), Santa (ending with ‘Sa’) Vedadya (Praṇava) and Śribija. He shall worship the Lokapalas with these Bijas. He shall worship Brahma and Vishnu in accordance with the rules and proper means of service in the north, south-west, south and north-east. He shall worship Devesha in the outer lines of the fifth Avaraṇa. He shall worship trident in the north-cast, thunderbolt in the east; axe in the south-east; arrow in the south; sword in the south-west; noose in the west; goad in the northwest and bow in the north. For the satisfaction of Shiva, the knower of the rules shall worship Kṣetrapala of Rudra facing the west, in accordance with the rules.
After performing the Avaraṇa worship, the devotee shall worship the lord of the gods again for allaying his mental disturbance. He shall know Praṇava as Shiva. After worshipping duly thus with scents and other services he shall offer Naivedya prepared in the proper manner. He shall give water for Achamana and the Arghya as before, and then offer Tambula and water in accordance with the rules.
After performing Nirajana the balance of the worship shall be completed. After meditating on the lord and the goddess he shall repeat the mantra hundred and eight times. Then he shall stand up with a handful of flowers meditate on lord Shiva with the mantra beginning with “Yo devanam” and ending with “Yo vedadau svaraḥ proktaḥ”. The handful of flowers shall be dedicated and he shall perform circumambulation thrice. He shall prostrate with eight parts of the body touching the ground. Endowed with great devotion he shall perform circumambulation again, make obeisance once more.
While sitting there, he shall adore the lord with the eight names. Then he shall pray thus: “O lord Shiva, good or bad whatever I have done is your great service.” After saying this, flowers shall be offered along with the water from the conch. After worshipping him who is worthy of worship, he shall repeat the eight names with significant meaning.