To make the simple syrup, combine the water and sugar in a small saucepan. Heat over medium heat, stirring occasionally, just until the sugar has completely dissolved. Remove the simple syrup from the heat and let it cool down to room temperature.
Once cool, pour the simple syrup into a mixing glass. Add fresh lime juice and a pinch of salt and stir well to combine. Store in a glass bottle.
To make your margarita, add 2 ounces tequila, 1 ounce triple sec and 1 1/2 ounces margarita mix in a cocktail shaker filled with ice. Shake well and strain into a salt rimmed glass filled with fresh ice.