Classic Margarita

Sea salt, for the glass
1 ounce tequila
1 ounce orange liqueur (Cointreau or Grand Marnier)
1 ounce fresh lime juice, plus lime slices for garnish
½ ounce agave nectar or simple syrup or more to taste
Ice

Instructions
Salt the rim of a glass by rubbing a lime wedge around the edge and dipping it onto a small plate of salt. Fill the glass with ice.
Place the tequila, Cointreau, lime juice, and agave in a cocktail shaker with ice. Shake and strain into the glass. Taste and stir in more agave nectar, if desired.