Rub the rim of each glass with a wedge of lime or grapefruit. Tap the rim of the glass into the sugar/salt garnish plate. Making sure to cover the entire rim of the glass. Add ice to the glass. Squeeze a grapefruit wedge into the glass, and leave the wedge in the glass. Pour the Grapefruit Margarita into the glass and serve. **Tip: You can add ice to the pitcher if you are serving the entire pitcher immediately. Otherwise add the ice to each individual glass. That way the pitcher of Grapefruit Margaritas will not get watered down.