You don't want to throw them away because you spent a lot of money on them (packaging supplies manage to be really expensive sometimes…). You don't want to send off packages just to use the leftover stuff because that would be ludicrous. So what do you do?
Use them to wrap gifts throughout the year
The brown craft paper that came as stuffing from a box from Amazon winds up being a perfect wrapping paper. Everyone is really into shabby chic and vintage and classic and there is nothing more classic than some crumpled kraft paper. Tie it off with a ribbon, us a button to do a cool little tie, decorate with stickers, you name it.
Save them to use as party décor!
Rolls of tape with very little left on them can wind up having the perfect amount for hanging balloons or streamers or banners. If you stack boxes you can dress them up as whatever you want. A couple ideas I have seen include Minecraft characters, dice, snowmen…
Turn them into family crafts!
From packing peanuts to shredded paper to packaging slips, use these leftover items to get your family gathered around the kitchen table making stuff. The creative results are just an added bonus for being able to invest in each other.
Let the kids go crazy!
If all else fails, at the very least, if you are too tired or busy or jaded to do anything fun or creative, throw all of those troublesome packaging supplies into a giant pile and let the kids have a heyday. Not only will you impress them with your generosity, but you can probably sneak in a nap on the couch, or at least veg on your phone without feeling guilty, while they explore their options. Even if it's just as simple as completely unrolling a roll of tape, stringing together the packing peanuts to make a necklace, or stacking boxes just to punch them down.
If you read all of this and find that it makes you nervous and that it will be a waste to do any of these ideas, than take a deep breath, pack all that stuff up, and put it in the garage for future use.