Crush ice cubes. Mash lime wedges in a jug. Crush sugar into lime with a wooden pestle. (Be careful not to crush lime skin too much, as this adds a bitter quality to the flavour.) Add crushed ice, then pour cachaca over top. Stir well. If you use vodka instead of cachaca, it’s called a Caipiroska; with rum, it’s a Caipirissima.
Kitchen note: Cachaca is a distilled spirit made from sugar cane.