3 sprigs fresh mint
2 tsp. sugar
1 1/4 oz. light or golden rum
3 Tbsp. lemon juice
club soda or seltzer water

In a tall, thin glass, muddle together the mint sprigs and sugar.  Add the lemon juice and stir.  Add crushed ice to the top of the glass.  Pour in the rum and stir again.  Top off with club soda or seltzer water, then garnish with a lemon slice and another sprig of mint.