Fill a cocktail shaker with ice.
Pour the tequila, Triple Sec, agave, and lime juice over the ice in the cocktail shaker, then cover and shake vigorously for 20 seconds.
Take a margarita glass and rub the wet side of the leftover lime rind over the rim.
Spread the Maldon flaky sea salt around the edge of a small plate and dip the prepared glass in it, coating the rim.
Fill glass with ice and pour the shaken margarita over it.
Keep them coming.