Place the lime slices in the glass and sprinkle the sugar on the lime. Muddle the limes until they are pretty well smashed.
Pack ice in the glass almost to the rim, then pour in the cachaça. Invert into a cocktail shaker and shake vigorously for about 10 seconds. Pour it all back into the glass and serve.
Pomegranate Caipirinha
Add the pomegranate juice with the cachaça and shake well. Pour into the glass and sprinkle some arils on top.