There are commercially available versions of all of this, but it is so much less expensive to make your own. You can do all of these things with regular bread too if you are one of my non-GF readers.
Breadcrumbs
Save dried out bits of bread (or epic bread baking failures) in a paper bag. Once they are dry, you can grate them with a cheese grater or put them in the blender to turn them into crumbs. If you want to expedite the process, just toast some bread until it dries out and do the same thing. Store breadcrumbs in a ziplock bag in the freezer and use whenever you need them.
Croutons
Cut some slice of bread into cubes. Place in a bowl and toss with a bit cooking spray or oil and herbs and spices of your choice (or just leave them plain). Bake in the oven at 350 F until they are dry (about 20 minutes usually), checking often to make sure they don't burn.
Stuffing
Make some plain croutons. You can either use them in your favorite stuffing recipe or in my favorite stuffing recipe, which is the following. Put the croutons in a casserole dish with sautéed diced onions and celery. Add some dried sage and cover with just enough chicken or veggie broth to moisten the croutons. Stuff your turkey with it or bake in a casserole dish. Baking temperature and time is pretty flexible, but if you're just making stuffing and not putting in with other things that are baking, 350 F for 20-30 minutes works well.
