This is from personal practice, I encourage people to look into epithets and associations to find what works for them, these are just what works for me or information I use regularly in my own practice or have noted down in my grimoire.
Epithets: Aidônaia - Of the Underworld. || Trimorphis - Three-Formed/Three-Bodied. || Enodia - Of the Wayside/Crossroads. || Nyktipolos - Night wandering. || Atalos - Tender/Delicate. || Khthoniê - Of the underworld. || Kourotrophos - Nurse of the young. || Skylakagetis - Leader of the Dogs. || Apotropaia - The one that turns away/protects. || Phosphoros - Light bringing/Light bearing. || Angelos - Messenger || Dark Mother (Modern addition).
Colours: Black, white, red, silver, saffron/yellow, midnight blue, orange, lavender.
Symbols: Daggers, crossroads, keys, torches, entrance ways, gateways, phases of the moon, strophalos (Hekate's wheel), triple-formed statue.
Stones/metals: Moonstone, black tourmaline, hematite, smoky quartz, silver, gold, jet, amethyst, labradorite, onyx, jasper, obsidian, selenite, sapphire, clear quartz, lapis lazuli, serpentine.
Animals: Dogs, serpents, horses, polecats, boards, owls, goats, toads, crows, ravens, bats, spiders, black lambs, bull, wolves.
Food/Drink: Honey, pomegranates, garlic, leek, onions, raw eggs, cakes, honey, cheese, fish, wine, dark chocolate, milk, almonds, bread, sesame seeds, olive oil, water, mead.
Perfumes/incenses: Queen of the night, cinnamon, myrrh, mugwort, honey, lime, lemon, orange, verbena, frankincense, lavender, jasmine.
Plants: Aconite, belladonna, dandelion, yew, hemlock, cyclamen, garlic, mandrake, mint, palm date, oak, cypress, roses, lavender, poppy seeds, herbane, datura, sage, laurel, rue, saffron, valerian.
Misc: Cauldrons, witchcraft tools, bones and crow/raven feathers (ethically sourced).
Devotional Acts: Invite her to help guide you while you do tarot readings, read ghost stories, learn new forms of divination, sit under the light of the moon if possible, have hekate bless the keys to your home, visit your local dog shelter/donate to shelters, spend time looking after/walking dogs, go looking in wild areas for bones, cook a meal with garlic and offer her some of it, spend time in a graveyard respecting those who have passed, follow moon phases and do moon spells, discuss your mental health with her, practice self love, sing or play instruments for her, offer acts of kindness.