This Jedi Mind Trick will enamour you to your date, as it will literally halve the amount she spends on drinks for you.
And it's ridiculously simple.
All you do is when you order your favorite diet soda at a restaurant (Fresca's good, but there are others..) hold up 2 fingers. Like Winston is doing. Say "I'd like 1 Fresca please", and the combination of the 2 fingers and words "One Fresca" usually result in the server bringing you 2 Frescas. At this point it's good to offer one to your date.
Image: Winston Churchill ordering 1 diet soft drink.