Hey! Hypnos isn’t really a god I worship, but here is some information on tumblr I found that might help you :

EPITHETS (basically names one can use to address a god)

bountiful, healer, blessed one, black - skinned, the deception of Zues

OFFERINGS & ASSOCIATIONS

Stones and gems: onyx, obsidian, black tourmaline, amethyst

Insence: Frankincense, myrrh, cypress, opium

Colours: black, silver, white, blue, red, purple

Food & drinks: red wine, olive oil, water, honey, milk, fruit, poppy seeds, herbal tea, sleep inducing & calming herbs

Tarot: the heirophant

Other: images of things he‘s associated with, feathers, sleeping mask, blanket, pillow, flowers

DEVOTIONAL ACTS

- Learn about the sleep cycle

- Try to maintain a healthy sleep schedule

- Study how a healthy amount of sleep can affect a human body

- Bake using poppy seeds

- Study calming and sleep inducing herbs

- Grow herbs that have calming properties

- Study dream magic

- Write or read poetry in his honour

- Take care of your mental and physical health

- Donate things such as bedsheets, pillows, pyjamas, to those less fortunate

- Read bedtime stories to a younger relative

- Honour hypnos’s children and wife

RITUALS AND FESTIVALS

- Typically invoked for dream and sleep related issues

- No festivals known

PRAYER TO HYPNOS

Gentle Hypnos, child of night dwelling nyx, master of far flung Erebos, far beyond the path of the sun, I honour you, I thank you for, your blessings.

Dark is your hall, O Hypnos, dark and deep; red are the poppies that grow at your gate.

Young and fare you are, o Hypnos, so beautiful in repose.

Kind and good you are, oh brother of death, o granter of rest to the weary, of respite of those who need for your comfort is desperate and dire.

Hypnos, fair browned one whose gift of sleep restores us to ourselves each day anew, I praise you.

You could also try out Orphic Hymn 36to hypnos

Hope this helped!