Rub a lime wedge along the rim of your shot glasses. Place sugar on a plate or salt rimmer and dip the shot glasses in the sugar to rim the glass. Line them up.
Shake things up:
Fill a cocktail shaker with ice and add the tequila and the cranberry juice. Shake it vigorously until the sides are fully frosted.
Serve:
Strain the mixture into the 4 shot glasses, holding back the ice. One, two, three, chug and repeat!