Preparation Combine gin, tonic syrup, and 1 cup ice in a blender and blend until smooth. Pour into serving glass and garnish with cucumber if desired. Editor's Note:Flavor will vary depending on your choice of tonic syrup and gin; feel free to add a squeeze of lime if desired. On a hot day, your drink will stay frozen longer if you start with chilled gin. (Adding additional ice will dilute the drink's flavors.)