Tequila: Blanco is best. Reposado works for a smokier flavor. Avoid añejo.
Chamoy: Quality matters here. Use a chamoy made with real fruit for the best depth of flavor.
Too sweet? Skip the agave and increase lime juice to 1 oz. A pinch of salt in the blender also balances sweetness.
Mocktail version: Replace tequila with 1 oz mango nectar and replace Cointreau with 0.5 oz fresh orange juice.
Pitcher version (8 servings): 2 cups tequila blanco, 1 cup Cointreau, 1 cup fresh lime juice, 2 cups mango nectar, poured over ice. Let guests swirl chamoy into their own rimmed glasses.
Storage: Best served immediately. The slush separates quickly if left to sit.