In advance of drinkin’ time, heat sugar with 1 cup water in a
small saucepan, stirring occasionally, until the sugar dissolves.
Measure out 7/8 cup syrup and transfer to a quart-size plastic
container. Place in the fridge to cool. Once the syrup has cooled,
stir in the lemon juice, lime juice, and 1/2 cup water to create
the sour mix.
To make each margarita, pour 2 ounces of tequila and 2 ounces
of sour mix into a cocktail shaker filled with ice. Vigorously
shake the mixture so the ice breaks up a bit, thoroughly chilling
the cocktail. Through a strainer, pour the mixture into an ice-
filled rocks glass and garnish with a slice of lime. If you like a
salt rim, slide a lime wedge around the rim of the glass and
invert over a shallow dish filled with kosher salt.