To make Simple Syrup

1. Combine 1 cup of sugar and 1 cup of water in a small saucepan. Heat on low, stirring, until the sugar dissolves. 

To Make Fresh-Squeezed Sour Mixture

1. Combine 1 cup of the Simple Syrup with 1 1/2 cups of the fresh-squeezed lime juice, 1/3 cup of fresh-squeezed lemon juice, and 1/4 cup of fresh-squeezed orange juice. 

Classic Margarita

1. Fill a cocktail shaker with ice.
2. Add 3 parts tequila (such as 3oz), 4 parts Sour Mixture (such as 4 oz), and 1 part (or 1 oz) Triple Sec.
3. Cover and shake until combined and chilled. 
4. Pour agave nectar on one paper plate and coarse salt on another. Dip the rim of your glass in agave nectar then dip in the coarse salt. 
   Alternatively, you can run a slice of lime around the rim of the glass then dip in salt. 
5. Garnish with a slice of lime.