St. Germain is a wonderful liqueur made from Elderflowers. It has a nice floral, citrusy flavor.
To make the simple syrup:
Combine one cup sugar and one cup water in small saucepan with a bunch of thyme sprigs. Bring to a boil to dissolve sugar, turn off heat and let cool. Remove thyme sprigs and store syrup in refrigerator.
Try serving this cocktail in a tall glass with ice and top with club soda. Just omit the club soda when shaking the ingredients and top off the drink with it.