Here’s a bright idea: Add zest with citrus.
Grate 1 tsp. zest from 1 grapefruit. On a small plate, mix the zest with 2 tsp. sugar. Halve the zested grapefruit. Slice 1 thin round from the center of the fruit; cut into quarters and reserve for garnish. Cut a small wedge from the remaining grapefruit and run it around the rim of 4 small glasses. Dip the rims in the grapefruit sugar.
Squeeze 1 cup juice from the remaining grapefruit into a large glass measuring cup or pitcher. Add the whiskey, lemon juice and the remaining 2 tbsp. sugar. Stir until the sugar dissolves, adding more sugar if desired. Fill the glasses with ice. Add the whiskey mixture and stir. Garnish with the grapefruit quarters.