Heat water and sugar in a small sauce pan until completely dissolved and the water is clear. Let cool. Pour into a pitcher with lime juice. Homemade lime mix done! Leftovers will keep 7-10 days in a jar in the fridge. Add tequila and orange liqueur. Pour over ice and garnish with lime slices. To make a single margarita, add 1/2 cup lime mix, 1.5 oz (3 Tbsp) tequila, and 1 oz (2 Tbsp orange liqueur) to a small glass of ice. To make frozen margaritas, freeze the lime mix into ice cubes. Blend the ice cubes with chilled tequila and orange liqueur until uniformly slushy.