Preparation

1. Using a Microplane, zest 1 piece of citrus. Mix with salt in a shallow bowl. Cut a few citrus wedges to rim the glasses. Set aside.
2. Using a sharp knife, slice the rinds from all the citrus. Throw the rinds into a medium saucepan with water and sugar and bring to a boil.
3. Reduce heat and simmer for about 10 minutes. Cool completely and strain into a high-speed blender, discard rinds.
4. Chop the fruit and throw in blender with tequila, ice and herbs (if using). Blend on high for about 1 minute until smooth.
5. Rub the rim of each glass with a citrus wedge, then roll or dip into salt. Pour margaritas and garnish with a slice of citrus and an herb sprig.