I have a water bottle that holds a liter, I drink half of it before going to the gym, the other half after my 20 minute workout.
I drink 16oz of red tea (caffiene free) and another half a liter in the morning at work. Lunch I have a fruit20 (another 16oz) plus the other half of my liter. I now have 3 liters done. I then fill my water bottle at home and drink my last liter with dinner and beyond. Of course this works when I remember everything