Chill silver mugs or goblets or heavy cut-crystal tumblers on ice in the freezer. Dissolve sugar (allow 1 lump per glass) in a little water. Fill each mug with finely crushed ice, add enough bourbon to cover the ice, and stir until the outside of the mug is heavily frosted. Then stir in the sugar syrup to taste. Tuck 5 or 6 sprigs of fresh mint into the ice so they protrude above the rim. Use a straw or just bury your nose in the fresh mint.