Place a martini glass in the freezer for 10-15 minutes, or fill it with iced water while you make the cocktail.
Measure and pour 60 ml of good-quality vodka, 30 ml of lychee liqueur and 30 ml of lychee syrup (from a tin of lychees) into a cocktail shaker.
Fill the shaker two-thirds full with ice, secure the lid and shake vigorously for 15-20 seconds, until the outside of the shaker feels frosty.
Discard the ice or water from the chilled glass, strain the cocktail into the glass and garnish with 1-2 tinned lychees.