One black coffee in the morning and a 500ml bottle of Diet Coke is now my usual daily intake.
All other caffeinated beverages have been replaced with water (hot or cold).
I used to drink two or three coffees, five or six teas, Diet Coke and/or a Red Bull every day so I've really cut down.
The first week of cutting down was horrible; I got nasty headaches at 18:00 like clockwork every day but that's all passed now.