For the sage-infused tequila:
1 1/2 cups tequila
3 sprigs fresh sage
For the margarita:
2 ounces sage-infused tequila
1 ounce fresh lime juice
1/2 ounce triple sec or Cointreau
1/2 ounce Agave in the Raw
1/2 teaspoon flaky sea salt or cocktail salt
1 sprig sage, for garnish
To make the sage-infused tequila: Combine the sage leaves and tequila in an air-tight container. Shake vigorously. Store in a cool, dark place for at least 24 hours and up to 3 days. (More than three days and the flavor will be a bit overpowering; you may want to cut your cocktails with half regular tequila after that point.) Keeping the same ratio, batch up as needed.
When you're ready to make the cocktail, if you'd like a salt rim, dump the salt onto a small plate. Prepare an (empty) rocks glass by rubbing a lime wedge around the edge of the glass, then dipping the wet glass rim in the salt and moving it around until the rim is well coated. Fill the rimmed glass with ice.
Combine the infused tequila, triple sec, lime juice, and agave nectar in an ice-filled cocktail shaker. Shake vigorously for 10-15 seconds.
Double strain (pour over a mesh strainer) into the ice-filled glass. Garnish with a sprig of sage, if you like.