Optional: 10 minutes before serving the margaritas, salt the rims of your glasses by dipping the rims of the glasses in lime juice then gently tapping them into salt before letting them air dry.
Stir the tequila, Grand Marnier, lime juice and agave together in a medium size pitcher. Then stir in the cucumber and limes and finally 2-3 cups of ice, if desired.
Serve immediately.
Add 2-3 pieces of ice to a cocktail shaker then pour in the tequila, lime juice, Grand Marnier and agave and cover and shake until well combined.
Strain the drink into a glass filled with ice and with a salted rim, if desired. Stir in the cucumber and lime slices along with 2-3 pieces and then serve immediately.