For sour mix, combine sugar and water in a small pot and heat over medium heat. Just heat until mixture is dissolved. Then remove from heat.
Juice lemons and measure out amount (you can adjust it to your tastes). Stir lemon juice and simple syrup together in a large jar and chill.
To make a margarita: measure out tequila, sour mix, lime juice, and orange liquor. Stir together. Run a lime wedge around your cocktail glass and dip the rim in coarse salt (opt.). Add ice to drink and stir well or shake lightly. Serve drink in prepared glass or strain into a martini glass. Garnish with lime.