Greek Gods 101: Helius
Helius is a god of the sun, oaths, and sight. Excluding the universal offerings, some common offerings include:
Depictions of the Sun
Glasses
Blindfolds
Contracts (Real or Fake)
Depictions of Horses
Sun Water
Lists of Goals or Objectives
Lights
Things Associated with Fire (Lighters, Coal, Twigs, Etc.)
Depictions of Chariots
Suncatchers
For devotional acts, some activities that can be done for him include:
Making Promises (and Keeping Them)
Watching the Sun Rise or Set
Sunbathing
Improving Your Vision
Making Goals and Plans to Reach Them
Going to the Beach
Swimming
Horseback Riding
Lighting Fires
He is celebrated in multiple holidays*:
Skira
Pyanepsia
Heliogenna
*Skira and Pyanepsia are Athenian holidays, but Heliogenna is not. Heliogenna is a modern holiday proposed by Hector Lugo. More information can be found here.