A purely mundane way to keep with it? Find things during your day to have a pint/bottle of water before you get to them. I finish one before I get to go eat breakfast and have coffee. I finish one during working out and before I get a shower. That's two more than I was before I started this, and the rest of the day, while I work and/or garden isn't as hard to keep to. It's a bit harder when there are errands, as I can't fill it as much and find myself wanting tea or coffee instead.