Combine some salt and taco seasoning in a saucer. Rim 6 martini or rocks glasses by running a lime wedge around the edges of the glasses, then dipping in the salt-taco seasoning mixture.
Combine the tequila, lime juice, Lime and Taco Simple Syrup, orange liqueur and several ice cubes in a cocktail shaker. Shake well until chilled.
Fill the prepared glasses with ice, then strain the drink through the top of the cocktail shaker into the glasses. Garnish with lime wedges.
Place the lime zest in a heatproof bowl.
In a medium saucepan, combine the sugar, taco seasoning, 1/2 salt and 2 cups water. Bring the mixture to a full boil. Pour the hot syrup into the bowl of zest and set aside to steep for 15 minutes. Strain into a glass jar or other container and let cool completely before making drinks. Simple syrup keeps refrigerated up to 4 weeks.