Fill a cocktail shaker two-thirds full of ice and add the vodka, triple sec and orange juice. Shake for approximately 15 seconds, and strain into a chilled cocktail glass. Top with the soda.
*To make lavender-infused vodka, pour a 750-ml bottle of vodka over a small handful of dried lavender in a large jar. Allow to sit for one week, then strain the vodka through a double layer of moistened cheesecloth back into the bottle.