Here's what you'll need for one cocktail:
- 2 oz tequila
- 3 oz fresh grapefruit juice
- 1 oz lime juice
- 1 oz simple syrup
- 1/4 tsp finely chopped jalapeño
- Club soda
- Salt for rimming
- Grapefruit wedge for garnish
Use fresh juices for the best taste. The jalapeño adds a spicy note, but you can adjust the amount to your liking.