I have done this too, but feel there should be a better option. Either a different Nalgene bottle, or (and probably more simply), a smaller scoop for the products.
In regards to the liquid flavor bottles, Food coloring bottles are pretty good about having a specific top on them to prevent leakage/drippage - almost like a little squeeze bottle. This would make use of the liquid flavorings much cleanlier. I do often pre-mix the flavoring, but sometimes life happens on the go as we all know.
Any mods out there with any input into this? Have I placed it in the wrong forum?
Thanks for the responses everyone.