Get glass ready: Rub lime, dip, and tap with salt.
Put 6 blackberries in a cocktail shaker.
Crush blackberries with a muddler.
Add Tequila, Patron Citronge, Lime Juice, Sweet & Sour Mix, Agave Nectar, and ice to the shaker.
Shake all ingredients for 10 seconds.
Pour into a salted margarita glass.
Add more ice to the glass.
Decorate with 2 blackberries and lime wedges.
Savour your Patron Blackberry Sandia Margarita!