Brine it in a mixture of water, salt, and sugar.
Before cooking put little slits into the skin and force a few pinches of dry rub in and rub it into the meat underneath the skin.
Before putting it into the oven toss a bunch of fresh herbs like rosemary, thyme, and sage and maybe a halved lemon into the cavity.
Pour a bit of stock to cover the bottom of the roasting pan along with onions, garlic, carrots, and celery roughly chopped. Put the rack over this in the roasting pan and the turkey on the rack.
Put in the oven and baste regularly with the drippings and stock.
Once out of the oven (several hours) transfer to a cutting board and cover with foil to let the meat rest before carving.
Take the roasting pan and either put it on the burner or pour it out into a pan and put it on the burner over medium heat and mash what's left of the vegetables in the bottom while bringing to a boil. You can throw in the cut up giblets as well if you want. Reduce the heat to a simmer once it boils and let the volume reduce to thicken it. You wont need much roux that way (melted butter and flour mixed together over heat), you could also used corn starch and water as a quick thickener.
I have also slipped a step in there a time or two where I smoked the turkey for a bit to add another level of flavor to the bird and gravy.
Hope that helps. If you have any questions call me
