Through my 19 prior marathons I've made many mistakes with hydration and fueling. To hopefully improve at the forthcoming Chicago Marathon I put together my fueling and hydration plan with some research and thoughts:
13. Alternatively, Chris of http://bqordie.blogspot.com/ fame recommended a far simpler fueling solution, which he's had good luck with. Carry two, and hold one EFS Liquid Shot container by 1st Endurance (see http://www.firstendurance.com/efs-liquid-shot.html). I haven't tried it as yet, but I'm tempted to as it's far simpler than the above approach (consume one container every nine miles, sipping along the way), and achieves nearly the same level of fueling and electrolytic levels.