In a simple libation like a gin & tonic, the spirit should really shine. Too often, cloying, crappy tonic obscures the botanical qualities of its partner, rendering the G&T much less refreshing than it should be. Luckily, long-time cocktail writer Camper English - who literally wrote the book on the beverage - has some tips on how to tweak your tonic and ensure your G&T lives up to its full potential.