Pour margarita or other coarse-ground salt on a small plate. Rub the rim of a cocktail glass with the lime wedge and dip the rim of the glass until it is coated with salt. Fill the cocktail glass with ice cubes.

Fill a mixing glass with cracked ice. Add the tequila, triple sec, lime juice, egg white, and powdered sugar. Shake and strain into the cocktail glass. Garnish with the lime wedge.