If you don’t know how to store weed properly, it can end up drying up or growing mold. Dry weed will have lost a good portion of the flavor and potency while moldy weed is unsafe to smoke.
If you’ve got quality weed and you want it to stay that way, you’ll have to try harder than a jewelry or sandwich bag. Especially if you’re planning to make it last for a while. Leaving the job to a bag alone will turn your sticky buds brittle within a weeks time.