Muddle Blackberries: In a cocktail shaker, muddle the blackberries and sugar together until the sugar starts to dissolve and the berries release their juices.
Mix Ingredients: Add the lime juice, orange liqueur, and tequila to the blackberry mixture. Fill the shaker with crushed ice.
Shake: Secure the lid on the shaker and shake vigorously for about 15 seconds, or until the shaker is thoroughly chilled.
Prepare Glasses: If desired, rub a lime wedge around the rim of two glasses and dip the rims into coarse salt or sugar.
Fill Glasses: Add crushed ice to the prepared glasses.
Pour: Evenly divide the blackberry margarita mixture between the glasses.
Garnish: Top each drink with a few fresh mint leaves, a lime wheel, and additional blackberries.
