well idk about on a longer term thing, but i keep all my trimmings in gallon zip lock baggies, just cause idk, mostly so when i throw them out i throw them all out at once, plus eventually ill be making hash when i get more leaves
anyways what i was sayin is, that the leaves in the baggies seemed to stay wet or not crumbly just by keeping them in an air tight bag so that the moisture couldnt escape, but im sure dark would be good too being at thc degrades in light