Out of limes tonight, I decided to start mixing something new. I at least had some other key ingredients.
1 1/2 oz Bombay Sapphire Gin
1/2 oz Cointreau orange liqueur
Juice of 1 lemon
2 tsp sugar
Squeeze a lemon into a highball glass filled with ice. Add the sugar, gin, and Cointreau. Top off with club soda and stir.