Layer cointreau and chartreuse in the glass. Ignite with a match, lick the palm of your hand and cover the glass with it.
Shake it a little bit after the glass has fastened itself. Remove your hand slowly while inhaling the air inside, shoot the entire contents, put two fingers in your mouth, inhale sharply and deeply, and then try to say: 'Hakkespett!' (In English: 'Woodpecker!') Good luck!