Leaves and stems can be chopped, ground up or at least broken into smaller pieces. Then when mixed in with a substantial amount of other decomposed/decomposing vegetative matter they really aren't identifiable. Even whole leaves, once detached it soon shrivels up and either dries out and becomes crumbly or it rots.
Obviously you shouldn't make it so apparent that if somebody glances at your compost pile/receptacle they just see a heap of straight cannabis by-products. Otherwise it wouldn't be easy to ascertain without a careful examination or even analysis by a lab.
A way to hide the remnants, but still recycle those nutrients back into the environment would be to simply bury it all a couple feet deep, in the garden if possible. It is highly unlikely it would even last long enough to be found, let alone used as evidence against you.