Citrus slices are also called wheels. They are ideal for garnishing cocktails because they are attractive. Cut the lemon, lime or orange crosswise into ⅛ to ¼ inch thick slices. Make a small cut in the middle of each slice, beginning near the center, cutting outward through the rind. The purpose of this is so that you can easily slide it onto the rim of the glass without juice squirting everywhere or ruining the look of the garnish.