Poke the olives through a cocktail skewer and set aside.
Make the marg:
Fill a cocktail shaker with ice and add tequila, Cointreau, lime juice, olive juice, and simple syrup. Shake vigorously until the sides are fully frosted.
Serve:
Strain the margarita into the glass. You can also serve it with the ice inside the shaker; this is up to you.