First, use a vegetable peeler to remove the peel of a lemon or an orange in 3⁄4-inch-wide strips, taking care to avoid the bitter white pith. Next, add the strips to a heavy bowl along with the amount of sugar specified in the recipe. Finally, use a muddler—the small, baseball bat-shaped stick used by bartenders—or a wooden spoon to vigorously crush the sugar and citrus peel together. The abrasive sugar helps rupture the citrus's cell walls and release the flavorful oils within. You'll know that's happened when the sugar takes on the color of the peels and becomes moist, slushy in texture, and intensely fragrant. The result is a concentrated, aromatic base that cuts the astringency of the alcohol in the punch and lends a bright, pleasing taste.