Rim half of one side of a 12-oz. rocks glass with tajin and set aside.

In a cocktail shaker, add tequila, dry curaçao, agave nectar, lime juice, a pinch of sea salt, and ice.

Shake vigorously for 20 seconds, and strain into a rimmed rocks glass.

Carefully top with fresh ice without disturbing the tajin.

Fill with Jarritos watermelon soda.

Garnish with a lime wheel.