Oakridge BBQ Game Changer Brine & Injection is favorite for literally thousands of Thanksgiving turkey cooks every year. I think the injection method is the best way to go versus the full immersion brine. The injection recipe is really easy, just mix 1/4 cup of dry brine mix into 16 ounces (2 cups) of your choice of injection liquid. Popular choices are low sodium chicken stock, apple juice, lemon-lime soda pop, ginger ale, white grape juice, peach nectar, or any other sweet or savory non-acidic liquid of your choice. The injection will be more flavorful if you can make it a day or two in advance. The extra time will allow the volatile oils to infuse into the liquid fully.
Then, inject at a ratio of 1/2 fluid ounce of finished injection per pound of turkey. For wild turkeys or natural free-range birds, you can go up to 3/4 oz per pound. Then, be sure to let the bird rest in the refrigerator for at least 8 hours prior to cooking so the injection has a chance to distribute more throughout the bird.
As far as seasoning goes, my favorite for a savory oven-roasted or smoked turkey is Oakridge Santa Maria and unsalted butter...
Mix 1 level TBSP of Santa Maria per stick of softened UNSALTED butter. Then, work the compound butter under the skin where ever you can and then smear it all over the outside of the bird. Be sure to dry the turkey skin as dry as possible with paper towels prior to applying the compound butter to the bird.
For a sweeter BBQ-style bird, you can't go wrong with either Oakridge Game Bird or another personal favorite is a combo of Oakridge Secret Weapon and Dominator. That combo is killer on any poultry... Same as above, dry the skin as good as possible, then apply your favorite veg oil or spray duck fat (even better) to the outside as a binder then dust liberally with rub(s).
If you wanted to go completely nuts, put the Santa Maria compound butter under the skin and then duck fat spray and Game Bird or Secret Weapon/Dominator on the outside.....
Hope this helps.