I usually make this for parties in the summer so you should probably pay more attention to what's going on down here.

Mix a 700 ml bottle of Pimm's No. 1 (that's the gin), 32 ounces of limeade (I use Santa Cruz organic limeade), and 36 ounces of ginger ale (I use three bottles of Reed's ginger beer) in a pitcher. Let it chill for an hour or so. Just before you serve, add a diced green apple and some cucumber slices to the pitcher, but make sure you have a ladle or a strainer so your guests won't be chagrined by what ends up in their cups.