I always had it warm with three coffee beans (tradition for luck, also enhances the anise flavor) and then lit on fire. I have an interesting sea-story about this in reply to Kenton...
You’re right it was 3 coffee beans, it’s been awhile. Never lit it on fire tho. I think Ouzo is the one they light on fire when they do flaming cheese and shout Opa! (or whatever it is they shout, I might misremember, I haven’t eaten any in awhile, but now I want some!)