Rub lime slice around the rim of a margarita glass (or just half the rim) and dip rim in kosher salt. Pour tequila, triple sec, lime juice, and sweet-n-sour mix into a shaker tin of ice. Shake, then strain into the glass. In addition to straight up, margaritas can be served frozen or on the rocks. Feel free to play around with different types of tequila. Try replacing the triple sec with Cointreau or Grand Marnier or with another flavoring, like melon liqueur.