An interesting video:
I do believe Loki is a God of fire, but He isn’t THE God of fire; that is Surtr.
As a Trickster deity, Loki has big appetites.
He is a very sexual God. He is pansexual, or, if you think about Him mating with Svadilfari to produce Sleipnir, He is omnisexual. I think His mating with Svadilfari, who was a Jotun magical horse, was a one off, though.
He is very fond of food, sweets and booze. According to shared personal gnosis, He likes spicy foods and is fond of Fireball whisky, so those are nice offerings to give Him.
Loki is also fond of creative activities, so nice offerings could be to draw Him or for Him, write Him a poem which you recite by the altar, or write Him a story which you tell Him.