This is a combination of advice from Joy of Cooking, Martha Stewart, and what I remember Mama doing for so many years.
1.) Preheat the oven to 450°.
2.) Rinse the turkey with cold water, removing the neck, liver, and gizzards. Dry with disposable cloth or paper towels. If you are stuffing it, do it now. Do NOT pack tightly or turkey will not cook properly. Loosely fill the neck end and secure with pins. Loosely fill the front end, overlap the legs together, and secure with kitchen twine. (Mama always sewed the turkey closed but Martha Stewart advises just to tie the legs together.)
3.) Cut the neck into pieces; Put it in the bottom of the roasting pan along with 4-6 carrots, halved crosswise, 2 large onions, cut into 8 wedges, and 2 stalks celery, halved crosswise, and 2 cups water. Set a roasting rack over vegetables in pan. (if you have one - makes lifting the baked turkey out of the pan very easy)
4.) Rub the turkey very lightly with olive oil. Season generously with salt, pepper, and just a little thyme. (leaves, not ground)
Put it into the prepared roasting pan.
5). Put the pan in the preheated oven, tent loosely with foil, (don't press the foil down on any sides), close the oven, and immediately cut the temperature to 350° or 325 ° for larger birds. (15 lbs. or more).
6.) Roast for 1 hour, then baste every 30 minutes with pan liquids, until an instant-read thermometer inserted into the thickest part of the thigh (avoiding bone) registers 125°. For turkeys weighing over 6 lbs, allow 15-20 minutes per pound. For turkeys weighing over 16 lbs., allow 13 to 15 minutes per pound.
NOTE: Add about 5 minutes to the pound if the bird you are cooking is stuffed. (says Joy of Cooking)
Mama always tested for doneness by pricking the skin of the thigh where the joint is and got a spoon and collected the juices to see if they ran clear - a good sign of doneness.
You can take the foil off in the last hour or so, to ensure that your turkey browns nicely. You might have to put pieces of foil around the legs or wing tips at some point if they are browning too much.
Prep time to get the bird stuffed and oven ready: One hour or if it's 6 in the morning and you're sleepy, allow 2!
Happy Thanksgiving and Bon Appétit!