umm, the smoke is going to smoother if you let the plant use up all the nitrogen at the end of flowering. yellowing and shedding leaves is a sign thats happening. unless you want that nasty ammonia smell in your burning weed you better stop using nitrogen in flowering.
crazybudz: nice buds...
starts smelling different about a week in. and from what i understand you want to keep the tiniest bit of moisture in the material for curing. because once it dries out completely, the process is irreversible. it's mostly guesswork through trial and error, unless you buy a caliber III hygrometer.