To make the simple syrup, fill a mason jar with water, 1 tbsp of granulated sugar, and several sprigs of fresh lavender. Let it sit for at least 24 hours in advance of serving.
In a glass over ice add ½ oz of lavender simple syrup and 1oz vodka, stir to combine.
Top with grapefruit soda or seltzer and garnish with a sprig of fresh lavender.
Recipe by DomestikatedLife at https://domestikatedlife.com/2015/10/05/grapefruit-and-lavender-refresher/