Rub the sugar cube gently over the lemon rind to infuse it with lemon oils. Place the sugar in a mug. Pour about 1 tablespoon of hot water over the cube, then stir until dissolved. Cut lemon in half, juice lemon halves, and pour juice into mug. Pour in whiskey and stir. Add a portion of a cinnamon stick. Spike a slice of lemon with cloves and float on top if you like.