I have made stuffing from scratch in the past, but doctoring up store-bought stuffing results is just as good an end product (without counter tops covered in stale bread...).
My Favorite Stuffing Additions
(can be made up to 4 days in advance and stored in the fridge)
your favorite store-bought stuffing*
*veggie broth (I like Rapunzel brand bouillon cubes, amt depends upon the stuffing)
*butter (optional, depending upon the stuffing you're using)
leeks, chopped (optional, you can always just go with onions)
fresh sage, chopped
steamed chestnuts, broken into pieces (found in a jar or box, depending upon your store)
We like a lot of stuffing, so I use my big soup pot and saute the chopped celery, onions, leeks and apples in a bit of olive oil, until the onions are translucent. At that point, I stir in the chopped sage and chestnuts (which I let my kids break up with their hands, if they're in the kitchen). Then, I simply dd the packages of store bought stuffing mix and broth (and butter, if your stuffing calls for it too) and stir it all together.
I make the stuffing at least one day in advance, to let the flavors meld...but you could make it up to 4 days in advance. Just store it in the fridge and reheat it Thanksgiving day (any temp 350-400), for about 30-40 minutes or until warmed through, loosely covered with foil if you like it moist...or uncovered halfway through the reheating if you like a crispy top to it.