--Who worships Soorya Bhagavaan keeping Nakt fast (eating once in the night) on Sunday, he becomes immortal.
--Who worships Bhagavaan Bhaaskar on Saptamee, especially on Sunday or Solar eclipse days, his all desires are fulfilled. Solar Eclipse days are especially dear to Soorya Bhagavaan.
(Bhavishya Puraan, p 214)

Soorya's 21 Name Stotra (Bhavishya Puraan, p 146)
--Read it 121 times in 7 days. It fulfills all your wishes

Any Sankraanti Falling on Sunday
--Worship Soorya by taking a flower, meditate on Soorya Bhagavaan, smell the flower, and throw it in Northeast direction. Then worship him with sandal paste, Dhoop, lamp, sweets and water.

Soory's Mantra
"Aum Kham Khakholkaaya Namah"
"Aum Hraam Hreem Sah Sooryaaya Namah"

There is the same result (fruit) for keeping complete fast and eating once.
Forgiveness, Truth, Kindness, Donation, Cleanliness, Control on Indriya, Worshipping Soorya, Havan, Contentment and A-Chaurya Vrat -
these 10 are general Dharm for every Vratee.

Soorya Namaskaar
Soorya Namaskaar is an age old Vaidik practice. It is also called "Arun Prashn" and it is often performed along with Mrityunjaya Jap, and Nava Graha Poojaa. This Soorya Namaskaar is part of Taittireeya Aaranyak of Yajur Ved, is considered as most significant worship of Soorya Bhagavaan. This Arun Prashn performed by a group of Vaidik scholars (usually 8, 16, 32 scholars in that order chant and perform it). It contains 32 Anuvaak or chapters with 130 Panchaati or paragraphs, where at the end of every Panchaati it is customary to perform Namaskaar to Soorya. With Poorvaang and Uttaraang Poojaa, this is then followed by Nava Graha Mantra.

In the olden days Soorya Namaskar was performed regularly by all communities - even Kshatriya and Vaishya too. That is a set of priests chant the Mantra and everyone participating members does the Namaskaar. Soorya represents both Vishnu and Shiv so both Vaishnavaites and Shaivites performed Soorya Namaskaar. Both men and women participate in this. Men doing Saashtaang Namaskaar and women doing Panchaang Namaskaar at the prescribed junctions. This was especially done by family members when someone is sick for a prolonged time or for success in a particular endeavor.

In the olden days, it was also performed together by the entire village at the temple, as the main set of priests chant and everyone does the physical Namaskaar. The positive vibrations created by these Vaidik chants are very important for health and prosperity. Even just listening to these chants is considered a great boon for health and success. Participating in this Vaidik Soorya Namaskaar itself is an exercise only with so many physical Namaskaar.

Soorya Namaskaar in Yog, containing 12 Aasan (representing the 12 Aaditya) is indeed a the most powerful Hath Yog exercise.