To rim your margarita glasses with salt, take a wedge of lime and rub it around the rim of the margarita glasses. Then, dip your glasses into your margarita salt and rotate them around a bit to get the salt to stick well.
Carefully add your ice to the margarita glasses, avoiding the margarita salt that you just rimmed your margarita glasses with.
To make the margarita, combine blanco, tequila, basil leaves, and blackberries into a cocktail mixer.
Muddle ingredients with a muddler until blackberries are well incorporated.
Add ice, lime juice and simple syrup to the cocktail mixer and shake.
Strain into serving glasses. Enjoy!
Tip: If you don't have a muddler (like we didn't, whoops!) you could probably find something in your kitchen that can get the job done. We used the top of a large mixing spoon, that had a thick top, so it could mash the fruit.