Start by placing the fresh mint leaves in the shaker. Add the simple syrup and a lime wedge too. Use your muddler to press down firmly and twist. This releases the mint oil and the lime juice.

Measure the elderflower liqueur and the gin carefully. Pour them into the shaker over the crushed mint. The smell will be very floral and sweet now. This is the heart of your summer smash drink.

Squeeze the fresh lime juice into the metal shaker. Fresh juice is much better than the bottled variety. It adds a zing that makes the elderflower pop. This balances the sugar in the floral liqueur.

Fill the cocktail shaker with large cubes of ice. Close the lid tightly and shake for fifteen seconds. You want the outside of the shaker to feel icy. This ensures the drink is perfectly chilled and blended.

Fill your tall highball glass with fresh crushed ice. Place a thin slice of cucumber against the glass side. This makes the drink look like a professional craft cocktail. It stays very cold against the ice.

Pour the drink through a fine strainer into the glass. This removes the bruised mint bits and any lime pulp. The liquid should look clear and very pale green. Leave a little room at the top for bubbles.

Top the glass with a splash of cold club soda. This adds the fizz that makes it a true smash. Garnish with a fresh mint sprig and a lime wheel. Serve it immediately with a straw and enjoy!