Infinit users - long run - how do you mix it?

I use a fuel belt.  Most of my long runs are 2 hours.  I'm thinking of 2 8oz bottles with 2 scoops each and then the other 2 8oz bottles with plain water.  Refill the plain water bottles at some strategic locations.

How do you do it? 

What is your game plan for longer runs (like 3 hours or 20 miles)?