To salt-rim the glasses, place the salt flakes in a shallow bowl or on a plate. Run a lemon wedge around the rim of a glass and then dip in the salt flakes so that it is evenly distributed.
To make the margarita, place the avocado, Tequila, Triple Sec, Agave syrup, grapefruit juice and ice in a high-speed blender and blend until slushy.
Pour into the salt rimmed glasses and garnish with slices of pink grapefruit. Serve immediately, preferably with avocado tacos.
