Choose your glass. (If you want a frosted glass combined with a decorative rim, chill the glass first in the freezer for about an hour.) On a small plate wider than the rim of the glass, pour a shallow layer of superfine sugar, cocoa, cinnamon, or kosher salt. Wet the rim of the glass with a slice of orange, lemon, or lime or just a little water (use a lightly dampened paper towel), then dip the rim evenly in the garnish. Lift and tap lightly to remove the excess before turning the glass over.
VARIATIONS
Use superfine colored sugar.
Mix equal parts sugar and chili powder.
Use cinnamon sugar.
