Klingon Tea Ceremony: (tlhIngan Dargh Seq) Performed by two friends, this ceremony is a reminder that "death is an experience best shared" (Heghlu'DI mobbe'lu QaQqu' Hegh wanI'), and partly as a test of courage, as the tea is toxic to tlhInganpu. Without an antidote the tea would be quite deadly to a tera'ngan. ("Up The Long Ladder" [TNG])
The tea (Dargh) was made with white blossoms plucked from a branch (which to me looked like a dried cactus plant). The blossoms were placed in brass teacups (Dargh HIvje') and (presumably hot) water was added. The cups were held with both hands, and sipped like one would drink milk from a bowl.
Klingon Raktajino: Raktajino was identified as a Klingon Coffee in several episodes, but the best example was from "Trials and Tribble-ations". I do not have the official recipe, here try these mixes. The first is actually Klah which was taken from the book "The Dragonlover's Guide to PERN" based on the novels from Anne McCaffery. The second was sent by Ka'Diin Kasara of the KIDC, and the newest was sent by Kor 'a of the IKV bortaS.