First, rim your glasses. Use a lime wedge to moisten the edge of a cocktail glass. Then roll or dip the edge of the glass into salt on a plate. Add ice to the glasses.
Combine lime juice, simple syrup, tequila and blue curaçao in a cocktail shaker. Add the lid and shake well.
Pour into ice-filled glasses and garnish with lime wedges.
Notes
About simple syrup: Clear simple syrup is preferred in this cocktail so the blue of the curaçao isn't dulled by the brown agave nectar. About fresh lime juice: Bottled lime juice concentrate has a more yellow color (sometimes with food coloring added) than fresh lime juice. When mixed with blue curaçao, the bottled stuff can add more of a green color to your margaritas. Therefore, fresh is best. Prefer sour mix? You can use sour mix in this recipe if you plan to make a bunch. When making sour mix, make sure to use all lime juice instead of a mixture of lime and lemon juices. And remember that fresh is best for blue cocktails. Then, simply replace the lime juice and agave nectar in the cocktail with sour mix.Make it frozen: To make frozen blue margaritas, add all ingredients plus about 3 cups of ice to a blender and mix it up.To make it non-alcoholic: Use Ritual tequila alternative or a similar zero-proof spirit to make a virgin blue margarita.To make it spicy: Use jalapeño tequila or spicy simple syrup to make a spicy blue margarita.